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Introducing Tactics: See What Adversaries Do After They’re Inside

GreyNoise has spent years observing the earliest stages of an attack. Our Global Observation Grid sees adversaries as they scan the internet, probe exposed systems, and attempt to exploit vulnerabilities at the edge. That visibility has traditionally focused on the left side of the MITRE ATT&CK framework, from Reconnaissance through Initial Access and it’s where we built our primary-source intelligence brand.

But we’ve known that is only half the equation.

Moving Further Right on MITRE ATT&CK

Earlier this year, we launched our C2 Detection Module, expanding our visibility beyond inbound scanning to the attacker-controlled infrastructure used after exploitation. GreyNoise reads the callback destinations embedded in exploit payloads to identify where a compromised device would call home, from malware-hosting servers to suspected C2 infrastructure.

This marked our first move right of Initial Access on MITRE ATT&CK, extending visibility beyond the exploit itself to the infrastructure supporting what happens next. Defenders can match outbound traffic from their edge devices against GreyNoise callback intelligence to identify connections to confirmed malware-serving infrastructure or suspected C2 servers.

See Host Telemetry from GreyNoise Deception Sensors on Your Network 

When we launched Project Swarm, we opened our deception platform to the global security community. Participants could deploy GreyNoise Deception Sensors across their own infrastructure that looked like the firewalls, routers, VPN gateways, and other internet-facing systems that adversaries target.

Project Swarm users gained full visibility into the sessions reaching their sensors, including raw payloads, HTTP headers, TLS metadata, and other behavioral artifacts. 

But a common ask from them was deeper visibility into what happened after an exploit succeeded. What shell commands did the adversary run? What files did they touch? What did they try to do next?

Introducing GreyNoise Tactics

Today, we are launching Tactics, giving anyone deploying a GreyNoise Deception Sensor deeper visibility into what attackers do after initial compromise. 

Tactics automatically maps qualifying attacker sessions captured by sensors in your workspace to the MITRE ATT&CK framework. Each detection represents one session and shows the tactics and techniques observed, along with the activity behind the mapping.

You can find Tactics under Observe → Tactics in the GreyNoise Visualizer. Open a detection to:

  • Follow the attacker’s complete command sequence
  • See the commands, scripts, and binaries the adversary executed
  • Inspect files created or modified, including their SHA256 hashes
  • Review outbound connections to internet destinations
  • Identify attempts to move laterally within your address space

Tactics begin populating when your workspace has a sensor running a vulnerable profile. Once an attacker compromises that profile and performs activity mapped to a MITRE ATT&CK technique, the session will appear as a detection.

Routine and unclassified sessions are filtered out, so the view focuses on meaningful adversary behavior rather than every connection your sensor receives.

See What Happens After the Shell

Because GreyNoise captures the attacker’s interaction with the host, Tactics can identify behavior across the post-compromise stages of MITRE ATT&CK.

That includes:

  • Execution: Commands, scripts, and binaries run after gaining access
  • Persistence: Scheduled jobs, new accounts, and other attempts to maintain access
  • Privilege Escalation: Attempts to gain greater control of the host
  • Defense Evasion: Actions intended to hide activity or interfere with protections
  • Credential Access: Searches for cloud credentials, private keys, service account tokens, and other secrets
  • Discovery: Commands used to inspect the operating system, processes, files, and surrounding environment
  • Lateral Movement: Attempts to reach other systems from the initial foothold, a view that keeps expanding as our deception network grows 
  • Collection: Files and data gathered from a system they think they’ve compromised 
  • Command and Control: Connections used to retrieve payloads or maintain access
  • Exfiltration: Attempts to move credentials, files, or other data off the sensor
  • Impact: Activity intended to disrupt the host, consume resources, or interfere with processes

With Tactics, GreyNoise now shows what adversaries do with access, not just how they find and exploit exposed systems.

Turn Observed Behavior Into Action

Every command, file, hash, path, and network connection captured by a sensor gives defenders a lead they can investigate inside their own environment.

  • SOC analysts and detection engineers can build and tune detections around the commands and techniques adversaries are using now.
  • Threat hunters can search production environments for observed hashes, file paths, binaries, and command patterns.
  • Threat intelligence teams can track which tactics and techniques are appearing across infrastructure relevant to their organization.

Because this intelligence comes directly from observed session activity, defenders can work from what the adversary actually did after gaining access. Mapping that activity to MITRE ATT&CK makes it easier to understand and use across existing security workflows.

What We Found After the Shell

Before launching Tactics, we analyzed weeks of post-compromise activity across our own Deception Sensor network in the Global Observation Grid.

Much of what we observed was commodity cryptomining, with adversaries treating each new foothold as more infrastructure to consume. A smaller set of sessions showed more serious behavior, going after cloud credentials, attempting container escapes, or creating backdoor accounts.

We break down these findings in After the Shell, a new GreyNoise research report published today. It examines what adversaries did after gaining access, which behaviors appeared most often, and what those observations mean for defenders.

Join the Swarm

Tactics is available for all users who have deployed a GreyNoise sensor. If you already have a sensor deployed, open Tactics under Observe in the GreyNoise Visualizer to see what it has captured.

If you’re new to Project Swarm, deploy a Greynoise Deception Sensor to start observing what attackers do after compromise.

Enhanced Detection Engineering at Scale in the Agentic Era

Resolving detection coverage gaps is a universal problem across the security industry. Before joining GreyNoise, I led Elastic’s Endpoint Protections security research team which was tasked with building visibility and detection capabilities in their Endpoint Detection and Response (EDR) solution. Researchers, red teamers, and attackers alike would constantly poke, prod, and reverse engineer our EDR’s detection capabilities then broadcast their evasions and bypasses to the masses. However, I always saw this as a unique challenge; iron sharpens iron, after all, and resolving these issues led to an improved product with expanded coverage. I believe this experience suits me well as I transition into my new role as the Head of Adversary Engagement at GreyNoise and lead our detection and deception engineering efforts.

Generative AI’s Impact on CVE Reporting

When GreyNoise was founded in 2018, 16,510 entries were added to the Common Vulnerabilities and Exposures (CVE) system. The number of entries (48,162) added in 2025 shot up to almost triple the number from 2018. Part of this astounding increase in CVEs can be attributed to the sharp rise in the number of CVE Numbering Authorities over the last decade from 23 in 2016 to over 500 by 2026. However, generative AI has had an undeniable impact on the annual number of reported CVEs over the past few years (130% growth from 2022 through 2025) which speaks to an existential crisis currently facing the security industry.

Large language models (LLMs) have lowered the barrier of entry for aspiring vulnerability researchers and exploit developers while significantly enhancing the capabilities of more experienced researchers and attackers. The mean time to exploit CVEs has sharply dropped to the point where it is now slightly negative, meaning that the average vulnerability was likely exploited in the wild before it was reported and assigned a CVE number.

In the face of impactful vulnerabilities and exploits popping up at rates faster than ever, we saw a critical need to revise our approach to threat detection. Our goals are the following:

  • Counteract CVEs by rapidly producing and deploying high efficacy GreyNoise Tags which have been evaluated against an extensive store of recent packet capture data collected from sensors operating on the GreyNoise Global Observation Grid (GOG).
  • Constantly evaluate and revise our tag corpus as needed to ensure accuracy and resilience against false positives.
  • Expand the GOG beyond the edge and build the infrastructure to support Deception Sensor coverage of a wider range of hardware and software platforms.
  • Coerce higher quality interaction with attackers through robust Deception Sensors spanning across multiple resources, which will provide deeper insight into more complex behavior and allow us to deploy tags across all stages of MITRE ATT&CK.
  • Proactively hunt for high confidence signs of previously unknown threats and deploy tags where appropriate.

This article will primarily focus on the first item above, with subsequent articles to come in the following months to highlight the other facets of our evolved threat detection approach.

Traditional Detection Engineering

The typical workflow for a detection engineer after CVE publication may resemble the following:

  • Review the CVE summary and any provided references.
  • Determine whether or not we have the infrastructure in place to capture exploitation of this vulnerability. If we do not, then we will need to research the relevant platform(s) and build new Deception Sensors before we push out tags.
  • Determine the likelihood of exploitation and potential for critical impact to our users.
  • Read any reputable research blogs or vulnerability write-ups (if available).
  • Locate and analyze relevant PoC exploit code (if available).
  • Reverse engineer the vendor patch (if available) and associated binaries or source (if available) to gather further context around the vulnerability and how it may be exploited.
  • Query the GreyNoise dataset for previous reconnaissance and / or exploitation from non-benign entities based on gathered indicators.
  • Craft detection logic which captures associated activity while taking extensive measures to ensure resilience against false positives.
  • Build a GreyNoise Tag, including all relevant metadata and references, and deploy to production.
  • Confirm that relevant Deception Sensors are actively deployed in the GOG to ensure proper data capture.
  • Tune the detection logic at a later point if data volumes become a concern or CVE is trending and we need to refine our detection logic.

As you can see, this is a lot of effort for a lone detection engineer to undertake even for a single CVE. With annual CVE additions on track to hit the hundreds of thousands starting in 2027, it is simply not feasible to continue down this path and provide accurate, up to date intelligence on the most critical emerging threats to our users. Evolving our approach is essential to keep pace with a rapidly shifting threat landscape.

Enhanced Detection Engineering

Allocating the research and development resources required to design, implement, and refine an efficient pipeline accelerated by agentic workflows is a necessary first step towards proactive threat detection at scale. We aim to leverage frontier large language models to reduce friction and remove onerous mental load bottlenecks for our detection engineers, which will allow us to focus on refining detection logic for the most pervasive threats and quickly provide accurate intelligence to our customers.

Agentic workflows will be critical to delivering real world impact in our revised approach to detection engineering. Agents are currently being designed and implemented to carry out the following tasks for a given CVE:

  • Pull down the CVE summary, associated metadata, and ingest data from each linked reference
  • Assess the CVE’s criticality (e.g. CVSS, KEV, operational impact) and whether or not we currently are capable of capturing exploitation
  • Locate and analyze references from trusted third party sources (e.g. vulnerability write-ups, exploit PoC code, patches, firmware samples)
  • Assess the objective quality of all ingested data and determine if sufficient context can be derived to proceed with drafting detection logic
    • If the data is currently lacking, this CVE will be inserted into a queue for re-assessment in the near future
  • Assuming the ingested data exceeds a predetermined quality threshold, an agent will proceed to build a packet query to filter through GreyNoise’s data to identify any recently observed relevant activity, with measures taken to reduce the likelihood of false positives
  • Refined detection logic will then be drafted by an agent which reflects both the key indicators derived from earlier research data ingestion as well as analysis of GreyNoise operational data

At this point, our detection engineers will step in to review the draft detection logic and a detailed summary of all tasks the agents carried out along with key indicators associated with exploitation of the given vulnerability. If further refinement of detection logic is needed, changes can be made at this point and reevaluated against our data to ensure sustained precision.

After a GreyNoise Tag is published, agents will continue to monitor for additional references to collect which may be relevant to a given CVE. These periodic collection tasks will similarly assess the quality and relevance of the data and determine whether it is additive in nature and thus necessitate further revision of our detection logic. Proposed tag updates will be drafted and our detection engineers will be notified for further review and to determine if an update needs to be published.

Moving Forward

This is the first step in a bold new direction for GreyNoise and our capability to assess and detect the most pervasive and critical threats. We look forward to sharing more with you in the coming months!

Now Available: Intelligence Dashboard in the GreyNoise Platform

Every day, GreyNoise's global sensor network observes scans and attacker traffic from hundreds of thousands of IPs across the internet. GreyNoise analyzes that activity to understand what each IP is doing, why it matters, and which tags and CVEs are connected to it. You can explore it all in the Visualizer.

The Intelligence Dashboard, available now, gives that intelligence a home. You can pin any combination of CVEs, tags, countries, IPs, and GNQL queries into one persistent, always-current view. Open it, and the activity you care about is already there, up to date.

See the Intelligence Dashboard in action

The first time you open the Dashboard tab, GreyNoise builds a Daily Intelligence Dashboard for you, stamped with today’s date and populated from what is currently notable across the sensor network. It is a starting point, not something you have to maintain. Edit it, save your own version, or let it regenerate fresh the next day.

Watch how to build a dashboard from scratch, add and configure panels, and save it for ongoing use.

What you can put on a dashboard

A dashboard is a set of panels. Each panel combines a panel type (how the data is shown) with a focus (what it shows activity for).

There are five panel types:

Panel Type What It Shows
Key Numbers Headline counts for your focus: observed IPs, source countries, top classification, and a top tag.
Activity Map A world map of the countries involved in the focused activity, colored by whether each country is a source of activity, a destination, or both.
Activity Trend A line chart of activity over the selected time range.
Tag Details The full intelligence card for one GreyNoise tag: description, classification, block/monitor recommendation, associated CVEs, references, and an activity graph.
CVE Details The intelligence card for one CVE: description, active-exploitation and CISA KEV status, CVSS score, EPSS score, threat IP count over the last day, and related tags.

And five ways to focus a panel:

Focus Description Available Panels
IP address One IP address Key Numbers, Activity Map
CVE One vulnerability (e.g. CVE-2021-22873) Key Numbers, Activity Map, Activity Trend, CVE Details
Tag One GreyNoise tag Key Numbers, Activity Map, Activity Trend, Tag Details
Country Activity involving one country Key Numbers, Activity Map
GNQL query Any custom GNQL query (e.g. tags:mirai classification:malicious) Key Numbers, Activity Map, Activity Trend

The GNQL focus is the most flexible option. Any query you already run in GreyNoise can become a live dashboard panel, so a standing query like tags:mirai classification:malicious turns into something you watch instead of rerunning every time. Just give the panel a name (a sensible default is suggested), and click *Add Panel*.

Make it your own

Every dashboard is built from panels, and adding one takes just a few clicks: pick a panel type and a focus, give it a name, and it lands on your dashboard already populated. You can drag panels to rearrange them, resize them, or expand any panel to full screen.

For the full step-by-step, including every panel type, focus option, and layout control, see the Intelligence Dashboard documentation.

Navigating a dashboard

Two controls in the header apply to every panel at once:

  • Time range: switch the whole board between the past 24 hours and the past 10 days.
  • Data source: choose which sensor data the panels query. GreyNoise’s global network by default, Community sensors, your own workspace sensors, or a combination. 

The Activity Map is worth a closer look. Countries are color-coded to show whether they are the source of activity, the destination, or both. Click any country on the map or in the sidebar to see the IPs the activity is coming from and the IPs being targeted, along with the organization that owns each one. Every IP links to its detail page, while “View all IPs” in the Visualizer opens the full result set as a GNQL query. When building a map panel, you can also filter it by source or destination country. For example, you could create a map that only shows activity targeting the regions where you operate.

Changes are not saved automatically. When you have unsaved edits, a banner appears with a “Save” button. The dashboard manager, accessed through the panel icon in the header, lets you switch between saved dashboards, search by name, create a new dashboard, or delete one. Dashboards are personal to you within your workspace. You can save up to 50 dashboards, with up to 24 panels in each.

Quick tip: which data source should I use?

  • Use GreyNoise to see what is happening across the internet at large.
  • Use My Workspace to focus a dashboard on what your own deployed sensors are seeing.

Community and My Workspace require a deployed Swarm sensor. Once you deploy one, access is granted within about 6 hours. 

Access and availability

The Intelligence Dashboard is available to all signed-in GreyNoise users. GreyNoise customers and Community users with a business email get at least 10 days of data lookback, while Community users with a consumer email get 2 days. Available data sources may also vary by account type.

To build your first dashboard, open the GreyNoise Visualizer and navigate to Query → Dashboard.

Ready to get started?

  • Current customers: Log in to the Visualizer, start from the daily view, and save your first dashboard.
  • Not a customer yet? Contact Sales to learn more.

Now Available: The Threat Brief Library in the GreyNoise Platform

Every week, GreyNoise publishes a threat intelligence brief called At The Edge. This covers what attackers are doing on the internet, including which products are drawing exploitation traffic, which vulnerabilities are being exploited, and what changed from the previous week. Each brief is built on primary-source data from our global sensor network and analyzed by our research team into named findings, IOCs, and recommended actions.

The Threat Brief Library is now available in the GreyNoise Visualizer. You can browse, search, filter, and download every brief available to your account as a PDF. Community users can access every At The Edge Clear edition, while customers get the full library.

What's in the library

The library includes three report types:

  • At The Edge: GreyNoise’s weekly intelligence brief covering exploitation activity observed across the edge during the previous week. Each edition includes analysis, IOCs, and recommended actions by role.
  • Executive Situation Reports: Event-driven briefs focused on a single campaign or vulnerability under active exploitation. Each report includes key judgments, vulnerability and campaign context, attacker infrastructure, observed tradecraft, implications, recommended actions, and the supporting activity data.
  • At The Edge Clear: The public edition of the weekly At The Edge brief, covering the week’s headline activity and key findings.

Inside a full At The Edge brief

Each brief is built on primary-source data from the GreyNoise Global Observation Grid, our global network of sensors that emulate the edge infrastructure attackers target. The sensors record all the exploitation attempts and our research team correlates them into named campaigns, confirms the CVEs involved, attributes the hosting infrastructure behind them, and writes the detection and remediation guidance.

A full At The Edge brief includes:

  • Bottom Line Up Front: the week's most significant activity and what to do about it
  • Recommended actions by role for for security leadership, SOC, vulnerability management, network security, threat hunting, and IAM teams
  • Named findings: the products, CVEs, CISA KEV status, campaigns, traffic volumes, and host classifications driving activity
  • Infrastructure attribution: the ASNs, hosting fleets, and network ranges behind the activity
  • Target assessments, IOCs, and detection guidance based on request patterns and client fingerprints that persist as source addresses rotate
  • Persistent activity updates on threats that remain active from previous weeks

Want to see what a week looks like? Read the latest At The Edge Clear edition.

Where to find it

Log in to the GreyNoise Visualizer, click your name on the top right, and open the Threat Brief Library. You can search by title or description, filter by category, and download any brief you have access to as a PDF. The newest briefs appear first. Briefs are also available through the API and an RSS feed, so you can pull them directly into your own tools or subscribe to new briefs as they publish.

The library is available to all GreyNoise users. Community users can read every At The Edge Clear edition, while GreyNoise customers get the full library, including weekly At The Edge briefs and Executive Situation Reports. Read the Threat Briefs documentation to learn more.

Contact us to get access to the full library.

5 Things I Show Every SOC Team When We Wire GreyNoise Into Their SOAR

I spend a lot of my time in SOAR consoles with security teams, and the same pattern shows up almost every time. The automation is already there. Playbooks fire, tickets open, enrichment runs. However, the decisions underneath are still shaky. Automation moves fast; it doesn't move smart on its own. A playbook that auto-routes a case is only as good as the context it routes on.

That's the gap GreyNoise fills. We don't replace your SOAR or your SIEM, we feed them. We tell your playbooks what not to worry about so the team can spend its hours on the activity that's actually aimed at them. Here are the five integrations I walk through in nearly every deployment.

1. IP enrichment that makes triage and response times faster

This is where almost everyone starts, and for good reason. Most SOCs still have analysts manually looking up IPs to determine whether an alert matters. The process is slow, repetitive, and often leads to inconsistent triage decisions.

We drop a /v3/ip lookup into the front of the playbook (single lookups or bulk, up to 10K at a time) so every alert gets enriched automatically with classification, tags, and threat level. Then you build your routing rules on top of that. The enrichment writes straight back to the case so the analyst sees the reasoning, not just the verdict.

The payoff is what teams care about most: faster response times, more consistent triage decisions, and a 40–60% reduction in alert volume once routine internet noise is identified and filtered.

2. Early warning when your vendors' CVEs start getting hit

Individual organizations often don’t see global exploitation spikes targeting their vendors until it’s too late. A surge in scanning or exploitation against a particular vendor's CVE can be an early sign of a zero-day or novel attack, but those patterns are difficult to detect when you're only looking at activity inside your own environment. By the time you hear about it after the vendor publishes an advisory, it may already be too late.

GreyNoise Event Feeds push an alert into SOAR the moment scanning or exploitation activity against your vendors' CVEs spikes. The playbook takes it from there: assess benign versus malicious activity, enrich with CVE and IP context, open a case, create a VM ticket, update blocklists, and notify the team in ChatOps.

The outcome is simple: detect rising exploitation activity days before vendors announce new vulnerabilities, patch and harden before attacks become widespread, and automatically separate real threats from benign scanning activity.

3. Detect compromised edge devices

This one resonates with anyone who's been burned by a compromised firewall or VPN appliance. You can't run EDR on those boxes, so when one gets popped and starts scanning the internet or calling home to attacker-controlled C2 infrastructure, you typically don't find out until blacklisted or it’s reported by an external party. 

We run two feeds into the SOAR for this. First, a webhook fires when GreyNoise observes your IP ranges conducting unsolicited scanning, a strong signal something behind that address is compromised. Second, a callback IP feed alerts whenever we detect a new attacker callback destination, which the SOAR correlates against your outbound traffic. Either one triggers automatic case creation and a containment ticket. That means catching compromise before it leads to reputation damage, responding automatically in seconds, and keeping persistent issues tied together in a single case timeline.

4. Build high-trust blocklists 

Every team wants to automate blocklist updates. Almost none of them fully trust the automation, because the nightmare scenario is auto-blocking a business-critical IP and taking down a legitimate service during business hours.

The fix is a validation step. Before an IP gets added to the blocklist, the playbook checks it against GreyNoise business services intelligence. If the IP is tied to a known business service, it routes to a human for manual review. If it's not, the block proceeds automatically. You get fast response to likely-malicious IPs without the over-blocking risk that keeps people from turning automation on in the first place.

The result is greater confidence in automated blocklist updates, reduced over-blocking risk, and faster response to likely malicious IPs. When I show this to a hesitant team, it's usually the thing that unblocks their whole automation roadmap. 

5. Build valuable threat intelligence into agentic workflows 

Most of the teams I work with are building agentic workflows now, and they keep running into the same wall: an agent is only as good as the context it can reach. Point it at incomplete or low-confidence data and you get confident-sounding nonsense.

GreyNoise plugs into those workflows through APIs, skills, or MCPs, so an agent investigating an alert can pull high-quality threat intelligence directly into its reasoning before it acts. The agent receives a trigger, queries GreyNoise, analyzes the context, and either returns an answer or kicks off a response workflow. This is grounded in observed attacker behavior rather than guesswork.

It's still early days for a lot of these deployments, but the teams seeing the most success are treating threat intelligence as a core input to the agent, not something bolted on afterward. The result is faster, more confident investigation and response grounded in high-quality threat intelligence.

The common thread

Which alerts deserve attention? Which CVEs are actively being exploited? Which IPs are worth blocking? Which signals point to a compromised device?

The reason these workflows work is because they're all built on the same foundation: real observations from across the internet. GreyNoise continuously watches scan and attack activity through our global sensor network, so when a playbook makes a decision, it's based on what an IP is actually doing in the wild, not just what it happened to do in your environment.

That's what gives teams the confidence to automate. Route an alert. Open a case. Block an IP. Escalate an investigation. The decision is backed by observed behavior, not a hunch.

I tell teams all the time that automation isn't the hard part anymore. Most organizations already have playbooks that can move fast. The challenge is making sure they're making the right decisions when they do.

If your SOAR is great at taking action but you're still questioning the inputs behind those actions, these are the first five workflows I'd look at. Explore our SOAR integrations >

Want to see any of these wired up live? Book a demo >

4 Ways GreyNoise Improves SOC Outcomes

Every organization connected to the internet faces the same background noise: automated exploitation attempts, vulnerability scanning, and credential abuse hitting the perimeter around the clock. The hard part isn't seeing the traffic, it's answering three questions fast enough to matter. What's hitting us? What's getting through? And what's already talking to adversary infrastructure?

GreyNoise continuously observes scan and attack activity across the internet, classifies the source IPs by behavior, and delivers that intelligence into your SIEM. The point isn't more data. It's separating the opportunistic noise, the stuff hitting everyone, from activity that might actually be aimed at you. Here are four ways SOC teams are putting that distinction to work.

1. Reduce alert volume and surface potentially targeted threats

The problem

Detections on perimeter scans and attacks are noisy by nature. Most alerts off edge devices aren't real threats, so they get ignored or suppressed. The alerts worth investigating are in there but they're just buried under scanning noise that hides anything resembling a targeted threat.

The detection

Filter your firewall and WAF logs down to inbound internet traffic, then match source IPs against GreyNoise and exclude the known mass scanners. Prioritize what's left by source-IP volume. Stripping out opportunistic scanning means analysts triage far fewer events, and the detection logic that remains has room to surface traffic more likely to represent targeted reconnaissance or attack activity.

The signal

Fewer alerts, better signal-to-noise. Every remaining alert comes from an IP GreyNoise has never observed scanning the internet, which is a much stronger indicator of potential targeted reconnaissance.

2. Detect allowed inbound traffic from known-malicious hosts

The problem

Perimeter gaps go unnoticed because nothing validates whether traffic that was allowed through should have been. Without external intelligence, traffic that passes through the firewall may not receive additional scrutiny, even when the source IP has a documented history of malicious activity. 

The detection

Correlate firewall and WAF allow logs against GreyNoise intelligence. Filter to inbound allowed events, match the source IPs against GreyNoise, and surface the malicious and suspicious matches, prioritized by source-IP volume. That tells you when something you let in originated from a host observed conducting mass scanning or exploitation.

The signal

A list of sessions where known-malicious or suspicious IPs were permitted through your perimeter. Each match is two things at once: a session worth investigating, and a firewall or WAF rule worth re-evaluating.

3. Flag authentication attempts from compromised hosts

The problem

Authentication failures and brute-force attempts from the internet are constant for any perimeter device. The trouble is telling opportunistic account access apart from attempts aimed specifically at your organization. Hosts running mass scans or operating as part of botnet or proxy infrastructure authenticate to VPNs and identity providers all the time, and standard detection logic doesn't flag it.

The detection

Correlate VPN and identity-provider authentication logs with GreyNoise. Filter to authentication events, match source IPs against GreyNoise, include the not-spoofable matches, and prioritize by source-IP volume. That surfaces auth attempts coming from hosts already observed scanning the internet, early enough to intervene on both successful and failed attempts.

The signal

A successful auth from a GreyNoise-flagged IP is an immediate, high-priority alert. Failed attempts from flagged IPs are worth a look too, as they can indicate active targeting of your identity infrastructure rather than random background noise.

4. Detect outbound connections to threat infrastructure

The problem

Outbound connection volume is so high that alerting on or investigating anomalous connections individually is impractical, so connections from internal infrastructure to known-malicious systems slip by. Most threat intel feeds don't help here either because they lack the real-time behavioral data needed to tell which outbound connections actually warrant a look.

The detection

Internal hosts reaching out to malicious infrastructure is a clear sign of compromise. Take outbound network and EDR logs, filter to public connections that egress allowed, match destination IPs against GreyNoise, and surface the malicious matches, prioritized by internal source-IP volume. When an internal host lights up here, the correlation points at a possible indicator of compromise - C2 beaconing, data exfiltration, or botnet participation.

The signal

Any successful outbound connection to GreyNoise-classified malicious infrastructure warrants immediate investigation of the internal host for indicators of compromise.

The operational payoff

Stacked together, these four detections move the needle on the things that security teams actually care about:

  • Reduce alert volume by removing opportunistic scanning from SIEM telemetry.
  • Improve signal-to-noise by prioritizing events more likely to represent targeted threats.
  • Surface perimeter gaps by identifying malicious infrastructure that made it through your defenses.
  • Detect compromise earlier by flagging suspicious authentication and outbound activity sooner.

None of this replaces the tooling you already run. GreyNoise is the context layer that makes your firewall, WAF, identity provider, EDR, and SIEM better at separating the internet's constant background noise from the activity worth your analysts' time.

Want to start deploying these detections? Talk to our team >

The Coverage Gap: Why Your Blocklist Is Missing 119,000 Malicious IPs Today

If you defend an enterprise network, you almost certainly trust an IP blocklist somewhere in your stack. That blocklist was almost certainly built for a different threat landscape than the one you are defending against today.

We measured it. On a single day, May 14, 2026, the GreyNoise Global Observation Grid recorded 119,842 malicious, non-spoofable IPs targeting edge infrastructure. We compared that set against eleven of the most widely deployed OSINT and commercial IP feeds in the industry. The average coverage was 2.0%. The strongest individual feed closed less than five percent of the gap.

That is not a flaw in any single feed. It is the cost of static curation in 2026.

What the Numbers Look Like

Feed List Size Coverage of Source Gap
FireHol Level 2 16,242 4.30% 95.70%
Blocklist.de (All) 22,404 3.91% 96.09%
FireHol Level 3 14,306 3.51% 96.49%
CINS Army List 15,000 2.97% 97.03%
FireHol Level 4 78,104 2.53% 97.47%
Avastel 1-Day Proxy/Bot IPs 500,000 1.85% 98.15%
ShadowWhisperer Malware/Hackers 6,894 1.40% 98.60%
FireHol Level 1 4,456 1.18% 98.82%
Binary Defense Ban List 2,719 0.32% 99.68%
Palo Alto High Risk EDL 2,776 0.28% 99.72%
Palo Alto Known Malicious EDL 4,000 0.24% 99.76%

Eleven feeds tested. None broke five percent. The list with the largest absolute size (Avastel, half a million IPs) caught fewer than two percent of the malicious traffic we observed in the same window. The vendor-curated EDLs that ship by default in many enterprise firewalls came in under half a percent.

This is not because those feeds are bad. They are doing the job they were designed to do, which is to flag IPs that meet a high bar for confidence. The problem is that "high bar" is often the result of a manual and slow review process.

Why Static Lists Are Losing Ground

The pace of attacker infrastructure has changed. Three forces are compressing the useful life of an indicator faster than any curated list can keep up.

1. AI-assisted scanning

Automated reconnaissance no longer requires a human in the loop. Threat actors can spin up scanners at a scale and speed that was operationally impractical even two years ago, then rotate the source infrastructure once it gets noisy.

2. Residential proxy botnets

A growing share of malicious traffic now originates from compromised consumer devices and rented residential IP pools. These IPs do not look like traditional badness. They sit inside ISP ranges that you cannot blanket-block without breaking legitimate traffic, and they recycle constantly.

3. Ephemeral cloud and hosting infrastructure

Attackers stand up VPS instances, run a campaign, and tear them down before most curation pipelines have rotated through their next refresh cycle. The same IP that was scanning Cisco IOS XE on Monday belongs to someone else's WordPress blog by Friday.

The result: list turnover at most curated feeds is measured in dozens of IPs per day. The threat infrastructure those feeds are trying to track is churning by the tens of thousands. A list refreshed weekly, or even daily, is staring at yesterday's attackers.

What GreyNoise Actually Is

GreyNoise is primary-source intelligence. Every IP in our dataset was observed by a GreyNoise sensor doing the thing we say it was doing. We do not aggregate other vendors' lists or infer from reputation. We have the receipts: raw session data captured at the moment of the event, whether that was a scan, an exploit attempt, or a brute-force payload.

The Global Observation Grid is a globally distributed sensor network specifically designed to attract and classify internet-wide scanning and exploitation activity. When an IP shows up in our 1D / Malicious / Non-Spoofable feed, it is there because we watched it do something malicious in the last 24 hours, and we can show the evidence behind the verdict for any IP, tag, or CVE in the dataset.

This matters for two reasons. 

First, the data is primary-source. We are not synthesizing a confidence score from third-party reports. The classification is grounded in observed traffic on infrastructure we control.

Second, the IPs are non-spoofable. The GreyNoise sensor architecture eliminates the class of IPs that look malicious in scan logs but are actually forged source addresses in reflection or amplification attacks. When we tell you an IP was scanning your edge, that IP was scanning your edge.

That combination is what makes the data viable for the use cases the static lists were built for, and a lot of use cases they were never designed to support.

Turning the Data Into a Blocklist You Can Actually Deploy

Closing the 98% gap is only useful if the intelligence can get into the box that does the blocking. GreyNoise offers two ways to do that, and they are intentionally separate products built for different audiences and different levels of customization.

The Primary Path: GreyNoise Platform Blocklists

The GreyNoise Platform, best suited for large security teams, enterprises, and governments, includes advanced blocklist functionality built directly into the Visualizer. These Query-Based Blocklists are built using GNQL: you write or refine the query yourself, validate the results, and convert that query into a managed blocklist with one click.

This is the right path for teams that already live in the Visualizer and want full GNQL expressiveness without leaving the platform. The workflow is:

  1. Run a GNQL query in the search bar. For example, last_seen_malicious:1d AND spoofable:false AND tags:*Cisco* will block recently malicious IPs hitting Cisco gear.
  2. Review the returned IPs to confirm the list looks right.
  3. Click "Create Blocklist," name it, set an IP limit, and submit.
  4. Wait 1-3 minutes for provisioning, then pull the tokenized URL (or use header-based auth with your API key) into your firewall. The list refreshes hourly from there.

Common starting queries documented by GreyNoise include recent malicious or suspicious activity, vendor-tagged activity (Cisco, Palo Alto, Fortinet, and so on), CVE-specific exploitation attempts, and geographic scoping. Anything you can express in GNQL, you can turn into a deployable list.

A configuration walk-through for Palo Alto Networks External Dynamic Lists is published here, and the same pattern applies to most NGFW vendors that support URL-based dynamic lists.

Try the GreyNoise Platform free — explore query-based blocklists and enterprise-grade threat intelligence firsthand. Request a trial >

The Alternative: GreyNoise Block for SMBs

GreyNoise Block is a separate product built specifically for small and mid-sized organizations that only need blocking capabilities.

Block gives you two ways to define a list:

  1. Templates. Pre-built blocklists curated by GreyNoise, ready to deploy with a click. You pick the template, name the list, set an IP limit that matches what your firewall can ingest, and Block produces a URL. The template handles the GreyNoise Query Language (GNQL) behind the scenes. For a firewall admin who wants a small, targeted blocklist running by lunch, this is the path.
  2. Advanced Query Builder. A drag-and-drop interface for building custom queries against the GreyNoise Global Observation Grid's data. You can scope by classification (malicious, suspicious, benign, unknown), source country, tag, CVE, actor, CIDR block, first-seen window, and lookback period. Group conditions and NOT operators are supported, so you can build queries like "malicious activity in the last day, excluding US-based infrastructure and a specific CIDR you operate." The builder shows you the resulting query and the IP count in real time, and the same "Block These IPs" button turns it into a deployable URL.

Deployment is the same either way: copy the blocklist URL, paste it into your firewall's external dynamic list configuration, and authenticate with either an inline ?key=YOUR_API_KEY parameter or a request header named key. Lists refresh hourly after the initial 5–10 minute provisioning window.

Try GreyNoise Block for 14 days with a free trial. Try it free >

The Bottom Line

The blocklists that defended the perimeter for the last decade were good products built for a slower-moving adversary. They are still doing useful work today, and we are not suggesting anyone rip them out.

What we are suggesting is this: if 98% of the malicious activity hitting your edge on a given day is invisible to your current feeds, the right response is to add a source that can see it, not to keep waiting for static curation to catch up to something that has fundamentally changed.

GreyNoise enriches the tools you already run with continuously updated, primary-source intelligence. No list maintenance overhead. No second curation team. The customers who have done the integration get the benefit of seeing what we see, in the systems they are already running.

By the way, there is nothing special about May 14th. The 119,842 IPs we saw on that day are not a number that will hold tomorrow. By the time you read this, the count has already turned over. That is the point.

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Data collected 2026.05.14. Source: GreyNoise 1D / Malicious / Non-Spoofable. Comparison destinations include FireHol Levels 1 through 4, Blocklist.de, CINS Army List, Palo Alto Known Malicious EDL, Palo Alto High Risk EDL, ShadowWhisperer Malware/Hackers, Binary Defense Ban List, and Avastel 1-Day Proxy/Bot IPs.

A New SonicWall Scanning Spike Echoes the Pattern That Preceded CVE-2026-0400

Between May 9 and May 18, 2026, GreyNoise observed a significant new spike in scanning of SonicWall SonicOS management interfaces. The May 12 peak — approximately 597,000 sessions — was the largest single-day total recorded on the SonicWall SonicOS API Scanner tag in the past 90 days, roughly 46× the typical daily volume for this tag in the 30 days before the elevation. 

Similar elevations in activity against this GreyNoise tag have preceded new vulnerability disclosures affecting SonicWall (Ten Days Before Zero, GreyNoise 2026). 

Activity on this tag spiked three times in an earlier sequence — on January 18, January 30, and February 14 — at 37, 25, and 10 days before the February 24 disclosure of CVE-2026-0400. The current spike may be a similar early warning.

The relationship is one observed precedent, not a rule. The current spike could be the first of a multi-event sequence like the Q1 pattern, a single event preceding a disclosure, or unrelated activity. Three documented spikes on this tag preceded a single CVE — a precedent, not an established cadence, and not a definitive rule.

GreyNoise is publishing the signal, not predicting a CVE.

Single-day session volume on the SonicWall SonicOS API Scanner tag. Three Q1 activity spikes — January 18, January 30, and February 14, 2026 — preceded the February 24 disclosure of CVE-2026-0400. The May 12 peak is the largest single-day total recorded on this tag in the past 90 days.

What We're Seeing

  • Tooling: Approximately 99% of requests carry a single browser user-agent — Chrome 119 on Linux x86_64 — the same fingerprint that dominated the January–February SonicWall scanning (94.5% of Q1 traffic, per Ten Days Before Zero). The tooling appears unchanged.
  • Source infrastructure: Approximately 56% of sessions originate from networks announced in the Netherlands and 44% in Ukraine — together more than 99% of total volume.
  • Concentration: A single ASN (AS211736) carries roughly half of total session volume. The IPs involved are overwhelmingly classified by GreyNoise as Suspicious.
  • Targeted services: Ports 80 and 8080 (HTTP) carry virtually all the scanning.

What Defenders Should Do

Immediate:

  • Restrict SonicOS management API and SSL VPN portal access to known administrative ranges. Eliminate public exposure of management interfaces.
  • Require MFA on all SSL VPN accounts.
  • Audit SonicOS configuration for new administrative accounts created since May 1, 2026.
  • Apply a dynamic IP blocklist at the network edge.

Over the next several weeks (the documented lead-time window for this pattern):

  • Monitor the SonicWall PSIRT advisory feed. Plan to patch within 24 hours of any disclosure.
  • Increase logging retention and outbound-traffic alerting on SonicWall appliances.

Reference

Project Swarm: Join the Collective. Defend the Edge

Here at GreyNoise, we’ve spent years building one of the most advanced deception networks on the internet. Our Global Observation Grid has over 5,000 sensors across 80 countries processing more than 500 million sessions per day, allowing us to see the internet's attack traffic before it reaches your doorstep. We've used that visibility to alert the world to mass scanning surges, vuln exploitation waves, and early reconnaissance patterns that signal what's coming next.

But there's a class of adversaries we can't catch alone.

The Perimeter Was Never “Dead”

The most advanced threat actors, state-sponsored adversaries like the Typhoon groups, have figured something out: the network edge is still a blind spot. Firewalls, VPN gateways, routers, load balancers — these devices can't run EDR agents. They often don't even support basic telemetry like logging. And they sit at the most critical exposure point: the network edge.

These adversaries have made edge devices their preferred point of initial access. They exploit vulnerabilities in firewalls and VPN gateways, hijack built-in tools on perimeter devices to maintain persistence, and send quiet, targeted probes designed to blend into the background. The Typhoon actors have demonstrated the most sophisticated version of this approach, building massive residential botnet proxies by compromising edge devices with little-to-no monitoring. APT41 has exploited zero-days in Fortinet VPNs, Cisco routers, and Citrix appliances. And well-funded ransomware crews are increasingly following the same path. The edge is where advanced adversaries go first, because it's where defenders see least.

Meanwhile, the exposure window keeps widening. The average patch time for edge devices is roughly 32 days, but exploit time is often near zero. For an entire month, your critical internet-facing infrastructure sits exposed to adversaries who are already watching.

The perimeter was never dead — it's the hardest attack surface to defend, and threat actors know it.

Deception Is the Best Answer

When the adversary specializes in staying quiet, you have to change the game. We believe deception is the best way to provide visibility into edge attacks — you can’t detect the threat; but you can make the threat reveal itself.

GreyNoise deploys sensors that emulate the exact assets attackers are looking for. When an adversary probes a sensor, they believe they've found a real target. Instead, they've exposed their tools, their payloads, their behavioral fingerprints, and their intent.

But here's the problem: no single organization can build the deception infrastructure needed to cover the internet's entire attack surface. We need more IP diversity, more device profiles, and faster detection rules than any one company can produce on its own.

That's why we're opening up our platform.

Announcing Project Swarm

Today, we're launching Project Swarm — a research initiative that opens the GreyNoise deception platform to the global security community.

Project Swarm transforms GreyNoise from a proprietary sensor network into a collective intelligence platform. We're inviting security researchers, universities, non-profits, ISPs, and OEM manufacturers to contribute to three pillars that make edge deception work at scale:

  • IP Coverage — Deploy sensors on your infrastructure to expand the geographic and network diversity of the Global Observation Grid.
  • Device Coverage — Bring device profiles for the edge assets you know best — firewalls, routers, VPN gateways — so sensors look like real, high-value targets to attackers.
  • Detection Velocity — Contribute detection rules and tags to identify attacker TTPs faster than GreyNoise can alone.

What You Get

When you deploy a GreyNoise sensor through Project Swarm, you get visibility into all the traffic hitting that sensor, and everything your sensor captures is yours to work with.

Every session is recorded with full fidelity: raw PCAPs, payloads, HTTP headers, TLS metadata, and behavioral artifacts. That means you're not just seeing that something probed you — you're seeing exactly what it did, what it sent, and how it behaved. 

For researchers, this opens up a world of possibilities. Here are some ideas to get you started:

  • Analyze captured payloads to reverse-engineer exploit attempts and study attacker tooling in the wild. 
  • Track how scanning and exploitation campaigns evolve over time by watching the same vulnerability get targeted with different techniques over time. 
  • Study the behavioral patterns that distinguish targeted reconnaissance from opportunistic noise — timing, sequencing, header fingerprints, TLS characteristics. 
  • Correlate early-stage recon activity against eventual CVE disclosures to build predictive models for what's coming next. 
  • Write and contribute detection rules based on what you observe, improving the GreyNoise tag library for the entire community. 
  • Compare your sensor traffic against the GreyNoise global baseline to identify what's specifically targeting your sensor versus what's hitting the broader internet. 

The possibilities are limited only by what IPs, emulators, and devices you can bring to Project Swarm.

Join the Collective

We believe deception is the best and only way to gain real visibility on the edge. You can't install agents on embedded systems. You can't rely on logs that don't exist.. But you can put something in the attacker's path that looks real enough to make them show their hand. When they probe a deceptive asset, they reveal themselves — their tools, their intent, their techniques — without ever knowing they've been caught.

The challenge is scale. To see the full picture, deception infrastructure needs to span more IP space, emulate more device types, and develop detection rules faster than any single organization can manage. That's what Project Swarm is about — turning the security community's collective reach into the world's most advanced deception network.

The era of defending in isolation is over. The adversaries targeting the edge are patient, precise, and well-resourced. But together, we can be everything, everywhere, all at once. Security is a collective team sport.

The Internet Changes Before the Advisory Drops

Before Cisco published its advisory for CVE-2026-20127 — a CVSS 10.0 zero-day cited in a Five Eyes joint warning — GreyNoise sensors had already observed eight distinct surges of Cisco-targeting activity. The earliest arrived 39 days before disclosure. Each one came closer than the last. A new study finds this pattern is not an anomaly.

What the Data Shows

Over 103 days, GreyNoise tracked 147.8 million sessions across 276 vendor-specific tags covering 18 network infrastructure vendors. Of 104 detected surge events, 68 preceded a vendor-matched CVE — spanning 33 vulnerabilities across 16 vendor families. Statistical testing confirmed the pattern is not coincidence.

  • Median lead time: 11 days. 49% of surges arrived within 10 days of disclosure. 78% within 21 days.
  • Session volume is the primary signal. Session volume carries the early warning. IP count alone is a weaker predictor, but when both spike simultaneously, the warning is highest confidence and the lead time extends to 21 days.
  • Countdown compression. SonicWall CVE-2026-0400: six surges from 37 to 3 days, peaking at 69x median volume. Fortinet CVE-2026-24858 (CVSS 9.4, zero-day): one day of warning.
  • Concentrated targeting shortens the window. Distributed surges averaged 21.3 days of lead. Concentrated hosting surges: 7.5 days. 11 ASNs appeared across 3+ vendor families.

Why This Matters

Mandiant's M-Trends 2026 found that mean time-to-exploit has gone negative. VulnCheck documented that 28.96% of KEVs in 2025 were exploited on or before publication day. The traditional model — wait for the advisory, then act — leaves a measurable gap. The signals that narrow that gap are already visible in GreyNoise data.

Download GreyNoise's Ten Days Before Zero report to discover the full findings.

What's Inside the Report

  • 33 paired CVEs across 16 vendor families with lead times and attack-type decomposition
  • Countdown compression case studies: Cisco, SonicWall, Fortinet, Ivanti, MikroTik
  • Infrastructure analysis: 11 cross-vendor ASNs, 4 attacker clusters, phase transitions
  • Statistical methodology and validation approach
  • Actionable framework for integrating pre-disclosure signals into patch prioritization

Just 21 IP Addresses Are Now Behind Nearly Half of All RDP Scanning on the Internet

A fleet of 21 IP addresses is now generating nearly half of all the RDP scanning traffic on the public internet. On April 7, 2026 alone, those IPs produced 1,856,167 of the 2,753,274 RDP Crawler sessions observed globally by the GreyNoise Observation Grid (GOG) — 67.4% of the worldwide total. Across a 48-hour window from April 5–7, the same fleet accounted for 49.7% of global RDP Crawler activity, while the other 3,644 sources on the internet produced the rest combined.

RDP — short for Remote Desktop Protocol — is how Windows lets people log into a computer remotely. Attackers scan the internet for exposed RDP endpoints, initiating connection requests at scale to map targets. Once they find an open service, brute-force password attempts typically follow. RDP has been one of the top entry points into corporate networks for years, which is why the sudden concentration of scanning activity in one small network matters.

The 21 RDP fleet IPs are part of a larger cluster of active addresses in a single autonomous system: AS213438, registered in RIPE WHOIS to ColocaTel Inc. of Mahe, Seychelles. This is the same ASN GreyNoise previously reported on for producing roughly 10.7 million sessions the week of March 5–11, 2026 — before activity collapsed 97.7% overnight on March 7 and went quiet for most of the month. In the first week of April, the ASN came back: smaller fleet, tighter geography, single-protocol focus on RDP. Then, just as before, it crashed — dropping 99.9% in a single day and going fully silent by April 9.

Key Takeaways

  • On April 7, 21 IPs in AS213438 produced 1,856,167 RDP Crawler sessions — 67.4% of global RDP Crawler activity that day. Across a 48-hour window (April 5–7), the fleet accounted for 49.7% of the global total.
  • The RDP fleet concentrates in four /24 network blocks. 
  • Total AS213438 volume scaled roughly 11x in 24 hours — from 180,293 sessions on April 6 to 2,011,365 sessions on April 7. RDP Crawler accounted for the overwhelming majority of this traffic.
  • The Netherlands' global share jumped from 7.17% to 53.86%. Romania's share fell from 29.89% to 15.78% — not because Romania dropped, but because the Netherlands grew ~15x and changed the denominator.
  • The fleet crashed on April 8 and went silent on April 9 — the same burst-and-crash pattern observed in March. RDP Crawler sessions from AS213438 fell from 1,856,167 on April 7 to 1,795 on April 8 to zero on April 9. Two burst-and-crash cycles from the same ASN, same IPs, same pattern, 30 days apart.

What the Data Does and Does Not Show

GreyNoise sensors observe unsolicited traffic hitting the public internet — scanning, probing, exploitation attempts, payload delivery, credential-harvesting requests, and RCE attempts. We do not observe successful compromises on real production systems. Every number in this post describes attacker activity reaching GreyNoise sensors, not confirmed impact on third-party environments.

GreyNoise does not attribute this activity to a named actor. ColocaTel Inc. is the RIPE-registered holder of AS213438. IP geolocation describes where infrastructure is routed, not where operators sit.

Why This Matters

For most of the past year, Romania was the largest single country-level source of RDP scanning traffic observed by GreyNoise. That changed in two days. Romania dropped from 29.89% to 15.78% of global share, and the Netherlands — where the 21 RDP fleet IPs are hosted — rose from 7.17% to 53.86%. AS213438 accounts for the majority of that country-level shift.

Two things make this notable. First, 21 IPs generating half of a global scanning category is not normal — typical source distributions are spread across thousands of IPs and hundreds of networks. Country-level or broad reputation feeds tuned to the old distribution are now pointing at the wrong place. Second, the same ASN was recently the loudest thing on the GOG, then fell silent, then came back smaller and narrower — and then crashed again. That repeating burst-and-crash rotation pattern is a defensive consideration on its own.

The Drop and the Resumption

The week of March 5–11, 2026, AS213438 was among the top source ASNs on the GOG, generating roughly 10.7 million sessions across mixed scanning behavior. On March 6, the ASN produced 3,756,496 sessions. On March 7, that figure crashed to 86,953 — a 97.7% single-day drop. The ASN stayed quiet through mid-March.

In the first week of April, it came back.

Date (UTC) Sessions Observed
Mar 28 4,934
Apr 1 46,005
Apr 4 49,532
Apr 5 156,322
Apr 6 180,293
Apr 7 2,011,365
Apr 8 130,006
Apr 9 (through 17:17 UTC) 91,868

Figure 1 — Daily scanning activity from AS213438 (ColocaTel Inc.), Mar 28 to Apr 9, 2026. Bars show total sessions observed by GreyNoise (RDP Crawler accounted for ~85% of volume). Teal bars indicate the ramp and peak; rose bars show the crash. April 9 is partial-day data, through 17:17 UTC.

The April 7 jump is the operational detail: session volume went from 180,293 to 2,011,365 (11.1x) in a single day. By the end of April 7, AS213438 was the single largest source ASN for RDP Crawler activity on the GOG.

Then it crashed. The RDP Crawler fleet — the core of AS213438's activity — went from 1,856,167 sessions on April 7 to 1,795 on April 8, a 99.9% single-day drop. The last RDP Crawler session from AS213438 was observed at 2026-04-08T06:22:49Z. By April 9, the fleet had produced zero RDP Crawler sessions. The remaining AS213438 sessions on April 8–9 are non-RDP activity from other IPs in the same ASN.

This mirrors March exactly: a steep ramp, a volume peak, and then a near-total collapse overnight. Two burst-and-crash cycles from the same ASN, the same IP addresses, and the same operational pattern — 30 days apart.

A note on verification.

April 7's activity spike coincided with a routine change in GreyNoise's sensor observation infrastructure — the kind of change that can, in some cases, make traffic appear to increase when it hasn't actually changed. GreyNoise cross-checked the spike using five independent tests, including comparison against the structurally identical March spike (which involved no infrastructure change), per-sensor rate normalization, and peer-ASN isolation analysis. The result: the spike is real. It presents identically to earlier observed behavior that did not involve an infrastructure change.

The verification also surfaced something interesting about the fleet's scanning speed. When new observation points came online as part of the infrastructure change, AS213438 traffic appeared on them almost immediately — suggesting these IPs are scanning the internet aggressively enough that newly reachable hosts are discovered and probed within minutes.

The current activity profile is also narrower than early March's. Instead of mixed scanning, it is overwhelmingly focused on RDP:

Tag (as observed by GreyNoise) Sessions in 48h
RDP Crawler 1,834,859
RDP Bruteforce Attempt 57,838
RDP Protocol 14,100
Web Crawler 6,122
Go HTTP Client 5,592
MySQL Protocol 3,067
MySQL Login Attempt 1,571

RDP Crawler alone accounts for roughly 85% of AS213438's total observed sessions in the window. Adding the other two RDP tags pushes the RDP-related share to ~88%.

Inside the Fleet

AS213438 had 32 active IP addresses in the 48-hour window, but only 21 of them are tagged by GreyNoise as RDP Crawler — the fleet behind the headline numbers. The remaining 11 IPs in the ASN are engaged in unrelated activity: web scanning, MySQL probing, Oracle WebLogic exploitation, and broad-spectrum reconnaissance.

The 21 RDP fleet IPs span four /24 network blocks:

Network Block City Active RDP IPs Sessions (48h)
193.142.147.0/24 Netherlands (Amsterdam) 8 715,147
185.196.220.0/24 Netherlands (Lelystad) 5 461,080
79.124.8.0/24 Netherlands (Lelystad) 4 368,557
45.134.225.0/24 Netherlands (Amsterdam) 3 290,092

Those four /24s hold 20 of the 21 RDP fleet IPs. One additional low-volume RDP Crawler IP (5.253.86[.]23, Lelystad) sits in a fifth /24. All 21 RDP fleet IPs are geolocated to the Netherlands.

The Amsterdam-and-Lelystad concentration, on infrastructure routed through a single ASN registered to one trading name, looks like hosting concentration — not a distributed botnet built from compromised devices. Two details reinforce that read:

  • Shared protocol fingerprints. GreyNoise observed the same TLS fingerprints across multiple higher-volume IPs in the fleet, consistent with centralized tool deployment. Commodity scanners with default configs could produce the same pattern.
  • A broad, non-standard port set. The fleet targets RDP on 3389 plus alternates 3390, 3391, 3392, and PostgreSQL on 5432 plus 5430, 5431, 5433, 5434, 15432, 25432, 30432, 35432, and 55432. The same alternate ports appearing across multiple IPs is consistent with a coordinated scanning configuration drawing from a shared target list.

Other Notable IPs in AS213438

One IP in the ASN — 31.56.110[.]107, geolocated to Colchester, UK — has been on GreyNoise's radar since May 2019 and operates as a broad-spectrum reconnaissance host classified as suspicious, not malicious. It is responsible for 259,925 of AS213438's 2,172,094 total sessions in the window, but contributes zero RDP Crawler sessions. The headline numbers are not affected by it: all RDP Crawler sessions come from the 21-IP RDP fleet, and the 67.4% global share holds whether you include the broader ASN or not.

The Country-Level Shift

RDP Crawler is one of the most consistent high-volume tags in the GreyNoise dataset. For months, Romania led it. Here is what the composition looks like now:

Country 14d Baseline (Mar 22 – Apr 5) 48h Window (Apr 5 – Apr 7)
Netherlands 7.17% 53.86%
Romania 29.89% 15.78%
United States 16.79% 7.37%
Russia 4.30% 6.25%
Bulgaria 7.74% 3.45%
All others 33.91% 13.29%

Figure 2 — Composition of global RDP Crawler activity observed by GreyNoise. The Netherlands' share rose from 7.17% to 53.86% in the 48-hour window, surpassing Romania as the top source country.

The Netherlands' daily rate went from ~64,894 sessions/day across the baseline to ~997,200 sessions/day in the window — a 15.4x increase. Romania's daily rate actually rose about 8% over the same comparison. Romania's share dropped because the Netherlands' volume grew much faster, not because Romania withdrew. This is a composition change driven by additive new volume.

For defenders, the effect is the same: any country-level RDP scanning weighting built from baselines before April 5 is misaligned with the current source distribution.

The ColocaTel Continuity

In the Ghost Fleet Hong Kong blog published March 25, 2026, GreyNoise reported on 109.205.211[.]101 — one of the most active source IPs in the dataset the week of March 12–18, 2026, producing roughly 7.97 million sessions (99.5% of which were RDP Crawler). That IP's route is announced by AS201814, a Polish hosting network operated by MEVSPACE sp. z o.o. The /24 containing it, however, is registered in RIPE WHOIS to an organization carrying the ColocaTel Inc. trading name at a Seychelles address.

Two RIPE organization records — one holding AS213438, one holding the /24 that contained 109.205.211[.]101 — are registered to the same ColocaTel Inc. name at the same Seychelles address (306 Victoria House, Victoria Mahe), with the same abuse contact (`abuse@colocatel.com`). The two records have distinct RIPE org IDs (ORG-CI158-RIPE and ORG-CI159-RIPE) and distinct maintainer handles, so GreyNoise cannot assert operational continuity from RIPE metadata alone. What we can say is that the same trading name, at the same Seychelles address, with the same abuse contact, has been linked to two separate high-volume RDP scanning incidents in GreyNoise data within the past 30 days — first on a /24 routed through MEVSPACE, now on /24s routed through AS213438 itself.

Recommendations

Security Operations

  • Add the four /24 blocks below to inbound RDP scanning watchlists or block rules. One rule materially reduces exposure.
  • Review authentication logs on internet-facing RDP services for activity from these blocks since April 5. Failed-auth patterns from these sources look like scanning, not users.
  • Audit non-standard RDP ports (3390, 3391, 3392) and non-standard PostgreSQL ports (5430–5434, 15432, 25432, 30432, 35432, 55432) on your edge.

Threat Intelligence

  • Track AS213438 for further profile shifts — it has now demonstrated two burst-and-crash cycles within 30 days, and the operational pattern suggests further rotations are likely.
  • Treat ColocaTel Inc. as a persistent registration identity worth tracking across RIPE records, not a single ASN.
  • Cross-reference the four /24s and AS213438 against pivot sets from the March Ghost Fleet HK reporting.

Security Leadership

  • Internet-facing RDP is continuously under scanning pressure regardless of which ASN is loudest that week. If you run it, assume it is being probed right now.
  • Country-level feeds that rank Romania, Russia, or China as the top RDP scanning sources are incomplete for this tag. The Netherlands has moved into the dominant position in this window.

Source Indicators (AS213438 / ColocaTel Inc.)

These are source IPs and CIDRs from which GreyNoise observed scanning. They are not compromise indicators — a match in outbound traffic from your environment is not evidence of infection. Treat them as inbound block/monitoring candidates.

Source Networks (AS213438 — RDP fleet /24s)

CIDR City Active RDP IPs (48h) Sessions (48h)
193.142.147.0/24 Netherlands (Amsterdam) 8 715,147
185.196.220.0/24 Netherlands (Lelystad) 5 461,080
79.124.8.0/24 Netherlands (Lelystad) 4 368,557
45.134.225.0/24 Netherlands (Amsterdam) 3 290,092

Top Source IPs (48h, AS213438 RDP fleet)

IP City First Observed Notes
193.142.147[.]111 Amsterdam 2025-05-28 Highest-volume RDP fleet IP in window
45.134.225[.]47 Amsterdam 2026-03-05 New infrastructure
79.124.8[.]148 Lelystad 2026-03-05 New infrastructure
79.124.8[.]151 Lelystad 2026-03-05 New infrastructure
193.142.147[.]177 Amsterdam 2023-03-17 Oldest IP in the fleet by first-seen
185.196.220[.]130 Lelystad 2026-03-05 New infrastructure

Destination Ports Targeted

Port Service
3389 RDP (standard)
3390, 3391, 3392 RDP (non-standard)
5432 PostgreSQL (standard)
5430, 5431, 5433, 5434, 15432, 25432, 30432, 35432, 55432 PostgreSQL (non-standard)
3306 MySQL

GreyNoise Tags (live data)

Attribution note.
GreyNoise does not attribute this activity to a named threat actor or nation-state. ColocaTel Inc. is the RIPE-registered organization for AS213438. The /24 holding the IP referenced from the prior Ghost Fleet HK reporting is registered to a separate RIPE organization carrying the same ColocaTel Inc. trading name and Seychelles address. IP geolocation describes where infrastructure is routed, not where operators are located. GreyNoise has not made contact with ColocaTel and cannot confirm whether the registered organization is aware of, complicit in, or unaware of the activity sourced from address space registered to its name.

Methodology.
All counts come from the GreyNoise Observation Grid (GOG). The 48-hour window is April 5, 2026 19:49 UTC through April 7, 2026 19:49 UTC. The 14-day baseline is March 22, 2026 19:49 UTC through April 5, 2026 19:49 UTC. Daily figures for April 7 reflect a full UTC day of observations. "21 IPs" refers to the count of unique AS213438 source addresses tagged by GreyNoise as RDP Crawler during the observation window; the broader ASN had 32 active IPs, with the remainder engaged in unrelated scanning activity. RDP Crawler is a stable long-running GreyNoise behavioral tag — tag-deployment artifacts are not a factor here. AS213438 registration details were independently verified against RIPE WHOIS on April 7, 2026. Historical AS213438 activity from March 5–11, 2026 and the early-March drop are drawn from the Ghost Fleet Hong Kong blog, published March 25, 2026. Volume verification details are described in the body of this report.

Introducing C2 Detection: Know When Your Edge Devices Are Calling Home to Attackers

When a firewall gets exploited, nothing happens, at least, nothing you can see. No EDR alert. No endpoint log. The device just quietly reaches out to an attacker-controlled server, downloads a payload, and waits for instructions. 

From the attacker's perspective, access is established. From yours, it's Tuesday.

Edge and perimeter devices, routers, firewalls, VPN concentrators, are the most actively exploited assets on the internet right now. They're also the ones your security stack has the least visibility into. EDR doesn't run on them. Their native telemetry is sparse. And when they're compromised, the only evidence is an outbound connection buried somewhere in your firewall logs. 

Today, we're launching C2 Detection, a new GreyNoise intelligence module that gives you two distinct, high-confidence signals that a device in your environment has been compromised.

Detect Compromise Through Outbound Traffic

C2 Detection is a new GreyNoise intelligence capability that surfaces the attacker-controlled infrastructure, malware-hosting servers, C2 nodes, and associated file hashes that compromised devices phone home to after a successful exploit.

Here's how it works: GreyNoise reads the exploit payloads that attackers send to its global sensor network and extracts the callback destinations embedded in those payloads. It then collects the malware hosted at those destinations and analyzes it to map the next stages of the attack chain — from staging servers to command-and-control infrastructure. This is payload-derived intelligence. GreyNoise doesn't need to wait for an exploit to succeed. It reads the payload directly, observes the post-exploitation chain, and delivers the results as a continuously updated dataset of confirmed callback IPs and associated malware hashes.

In the Visualizer, you'll see this as callback IP intelligence and malware hash data — two new layers that extend GreyNoise beyond inbound scanning into outbound threat detection.

Turn Outbound Traffic Into a Detection Signal

  • Detect active compromise from outbound traffic. Export your egress logs from edge devices and match destination IPs against the GreyNoise callback dataset. If there's a hit, the attack stage tells you how serious it is and what to do next.
  • Enrich your SIEM and SOAR with callback context. Pull callback stage and metadata via the API and use it to branch your playbooks. A Stage 1 match (confirmed file download) opens a case. A Stage 2 match (suspected C2 activity) triggers immediate escalation and containment.
  • Investigate historically. Callback infrastructure persists for weeks or months, far longer than scanning IPs. Use time range filters and the callback_ips query parameter to trace when GreyNoise first observed the infrastructure and which scanner IPs are linked to the same attack network.

Three Stages, One Severity Framework

Every callback IP is classified into one of three stages based on what GreyNoise has confirmed:

Stage What It Means Recommended Action
Unconfirmed IP appeared in a payload, but no file was successfully downloaded. Investigate. Don't escalate yet.
Stage 1: File Downloaded GreyNoise confirmed this IP is actively serving file payloads. Treat contacting devices as potentially compromised. Open a case.
Stage 2: C2 Suspected Behavioral analysis including VirusTotal detections, sandbox network activity, and malware associations indicates active C2 infrastructure. Assume active exploit presence. Escalate immediately.

This stage-based model gives you a built-in severity framework. Instead of a binary "good or bad," you get a signal calibrated to where the attacker is in their kill chain so your response matches the actual risk.

Two Signals. One Answer: You’re Compromised

C2 Detection strengthens a use case GreyNoise customers already know, detecting compromised assets by adding a second, independent signal:

  • Signal A (existing): Your organization's IP appears in GreyNoise as a scanner. That device has been recruited into a botnet and is scanning the internet on the attacker's behalf.
  • Signal B (new): Your outbound traffic matches a confirmed callback IP. That device is calling home to attacker-controlled infrastructure.

C2 Detection expands GreyNoise coverage beyond inbound activity, bringing high-confidence visibility into outbound communication with attacker-controlled infrastructure.

What This Adds to GreyNoise

This is entirely net-new. GreyNoise previously tracked only IPs actively scanning the internet, inbound threat intelligence. C2 Detection is the first GreyNoise capability focused on post-exploitation, outbound-facing threat intelligence. It introduces:

  • A new dataset: Callback IPs
  • A new classification model: Three attack stages
  • New data types: Malware files and hashes (with VirusTotal correlation)
  • A new query parameter: callback_ips

None of these existed in GreyNoise before.

Same Workflow. Stronger Signal. 

If you're already enriching alerts with GreyNoise, the integration model doesn't change. The Callback IP dataset is accessed through the same API and Visualizer you already use. It's a different dataset, a different API call, but the workflow pattern is identical: take an IP, ask GreyNoise about it, act on the answer.

The difference is that Greynoise now extends beyond inbound activity to surface high-confidence signals from outbound traffic. What was once context is now a detection signal.

Start Using C2 Detection

C2 Detection is available as a dataset add-on for existing GreyNoise customers, with access delivered directly in the Visualizer and via API.

Already a customer? Contact your account team or email support@greynoise.io to enable access.

Not a customer? Get access with an Enterprise Trial.

(An existing GreyNoise Community Visualizer Account is required, create one free here.)

Want the technical details first? Explore the documentation:

The Invisible Army: Why IP Reputation Fails Against the Rotation Economy

GreyNoise observed 4 billion sessions targeting the edge over 90 days. The data challenges a core assumption of network defense: that you can tell attackers from legitimate users by where the traffic comes from.

What is a Residential Proxy

A residential proxy is a compromised home internet connection used as a disguise. Attackers route malicious traffic through ordinary home broadband, mobile data, and small-business connections — the same IP address ranges used by employees, customers, and partners. To a reputation feed, the source IP is indistinguishable from a legitimate user's connection — the same ISPs, the same address ranges.

What the Data Shows

39% of unique IPs targeting the edge come from home internet connections — nearly double their 22% share of sessions. Each residential IP averages fewer than 3 sessions before disappearing, and the median is just 1. They are everywhere, briefly.

78% of residential IPs are observed at most twice across the entire Global Observation Grid before rotating. By the time a reputation feed flags a residential IP, the malicious behavior has already rotated to a new address. The rotation rate makes feed-based detection structurally ineffective.

0.1% of residential sessions carry exploitation payloads, versus 1.0% from hosting infrastructure. Residential proxies map the terrain; the exploitation payloads come later from hosting infrastructure.

Traffic from IPs geolocating to India drops 34% between daytime peak and overnight trough. The most likely explanation is that the infected machines are physically powered off. Server traffic varies less than 3%. The device owners are victims — these are home PCs infected with worms, not willingly enrolled proxy nodes.

SMB worm propagation runs 84% residential, with zero overlap between SMB and Telnet source IP populations — confirming completely separate device populations rather than general-purpose scanning infrastructure.

Why This Matters

The residential proxy problem is not theoretical. Google Threat Intelligence Group disrupted IPIDEA in January 2026 — a network with 9 to 11 million daily active proxies used by over 550 distinct threat groups. The DOJ dismantled 911 S5 (19 million IPs across 190 countries) and indicted operators of AnyProxy/5Socks (over 7,000 proxies, $46 million in revenue). Mandiant M-Trends 2025 documented state actors routing operations through residential infrastructure. Every major takedown produces the same result — temporary disruption, then regeneration.

What's Inside the Report

  • The landscape: residential vs. hosting traffic at internet scale
  • The rotation economy: why IP reputation is structurally broken against residential proxies
  • The sleep cycle: circadian patterns in compromised home PCs
  • The supply side: worm propagation and IoT botnets as separate ecosystems
  • Commercial proxy fleets: SDK-enrolled devices as exit nodes
  • VPN reconnaissance: residential IPs probing enterprise perimeters
  • When networks die: ecosystem resilience after takedowns
  • The detection gap: what GreyNoise sees, what it cannot, and what defenders can do

The report presents both the data and its limitations — including a Censys ground-truth validation and an explicit discussion of what GreyNoise can and cannot observe.

Ghost Fleet: Half of All New Scanning IPs Last Week Geolocated to Hong Kong — Nearly None Completed a Connection

Last week, the GreyNoise Observation Grid (GOG) observed something unusual: 242,666 new scanning IPs geolocating to Hong Kong appeared in seven days — nearly half of all new scanning IPs observed by GreyNoise that week. And 99.7% of them never completed a single TCP connection.

These IPs are ghosts — they appeared in GreyNoise data but never proved they were real. Because they never completed a TCP handshake, GreyNoise cannot verify that the traffic actually originated from those addresses. They carried no payloads, triggered no detection signatures, and performed no exploitation. All they left behind were a quarter-million unverified IP addresses now sitting in observation datasets.

Geographic references throughout this post describe where IPs are registered, not where the traffic necessarily originated or where operators are located.

Here's why that matters: any detection system that observed this traffic and doesn't distinguish between verified and unverified source addresses just absorbed a quarter-million ghost IPs into its dataset. Meanwhile, the 702 IPs geolocating to Hong Kong that actually completed connections — the ones observed scanning MySQL, SSH, SMB, and RDP, hitting GOG sensors in 20+ countries — could easily get lost in the noise. One provider alone, UCLOUD, surged 472% in session volume to become the largest ASN by session volume in GreyNoise data, with 38% of its IPs classified malicious. That's the signal. The other 242,000 IPs are the noise.

On top of that, the entire scanning landscape reshuffled last week. A top ASN disappeared overnight. Traffic from IPs geolocating to Australia dropped 72%. New infrastructure geolocating to Poland and Germany appeared. The scanning sources that dominated the prior week were not the same ones that dominated last week.

Key Findings

  • 242,666 new IPs geolocating to Hong Kong — 48.9% of all new scanning IPs observed by GreyNoise last week. 99.7% never completed a TCP handshake.
  • One organization, GNET INC., contributed 143,340 IPs — 28.9% of all new IPs observed by GreyNoise. Zero were classified malicious.
  • Only 702 IPs geolocating to Hong Kong (0.3%) completed TCP handshakes. Of those, 362 are classified malicious.
  • UCLOUD (AS135377) surged +472% in session volume, becoming the top ASN by session volume in GreyNoise data — with only 1,746 IPs but 38% classified malicious.
  • The scanning landscape rotated: a top ASN from the prior week disappeared entirely, traffic from IPs geolocating to Australia dropped 72%, and new infrastructure geolocating to Poland and Germany appeared.

The Ghost Fleet

Between March 12 and 18, GreyNoise observed 242,666 new IPs geolocating to Hong Kong — nearly equal to the rest of the world combined (253,646). Six hosting providers account for 93.3%:

Organization ASN New IPs Spoofable Malicious Tags
GNET INC. AS9294 143,340 99.998% 0 Virtually none
Yancy Limited AS138415 34,051 99.998% 1 Virtually none
Cloudie Limited AS55933 20,517 99.91% 45 Minimal
Zillion Network Inc. AS54801 10,329
LARUS Limited AS17561 9,433 100% 0 None
Netsec Limited AS45753 8,759 99.96% 1 Minimal

Figure 1: New IPs geolocating to Hong Kong, by organization. GNET INC. alone contributed 28.9% of all new IPs observed by GreyNoise.

When GreyNoise labels an IP "spoofable," it means the IP was observed sending traffic but never completed a TCP three-way handshake — the source address is unverified. Of these 242,666 IPs, 241,964 are spoofable. They are classified "unknown," categorized as "hosting" infrastructure (92.3%), and carry almost no GreyNoise tags.

One Organization, 143,340 IPs, Zero Malicious

GNET INC. (AS9294) is the single largest contributor — one organization that added 28.9% of all new IPs observed by GreyNoise in a single week:

Metric Value
Total active IPs (including pre-existing) 163,051
Spoofable 99.998% (only 3 completed TCP handshakes)
Classification 100% unknown
Malicious IPs 0
GOG sensor countries reached Primarily United States
Tags QUIC Protocol on 30 IPs. Nothing else.

No exploitation. No brute-force activity. No web crawling. Incomplete connections only.

Names That Don't Match Registration Geography

Several ghost fleet entities are registered under names that don't align with where their IPs geolocate:

Entity ASN Total IPs Discrepancy
LUOGELANG (FRANCE) LIMITED AS135097 62,617 "France" in name — 0% of IPs geolocate to France (62% HK, 38% US)
LARUS Limited AS17561 19,687 Split between Hong Kong (9,832) and Russia (8,751)
Taiwan Li Run Ltd AS131147 5,119 "Taiwan" in name — 4,096 IPs geolocate to mainland China, 1,023 to Hong Kong

The Signal Behind the Noise: UCLOUD

The ghost fleet is the noise. The signal is UCLOUD (AS135377).

Spoofable vs. non-spoofable IPs geolocating to Hong Kong — 242,000 IPs that did not complete TCP handshakes vs. 702 that did.

UCLOUD contributes just 1,746 IPs — 0.4% of the active IPs geolocating to Hong Kong in GreyNoise data. But it accounts for an outsized share of observed scanning and exploitation attempts:

Metric UCLOUD (AS135377) Spoofable Fleet Average
New IPs 1,746 8,759 to 143,340 per ASN
Malicious classification 38% (663 IPs) <0.1%
Spoofable 43.5% >99.9%
GOG sensor countries reached 20+ Primarily 1 (US, 99.8%)
Unique protocol tags 14+ active tags 0-2 tags

Figure 3: UCLOUD multi-protocol scanning activity observed by GreyNoise, spanning 14+ protocols.

The contrast is stark. The entity generating 82x more IPs (GNET INC.) has zero classified malicious. The entity generating 82x fewer IPs (UCLOUD) has 663 — observed scanning MySQL, SSH, SMB, and RDP, with traffic reaching GOG sensors in more than 20 countries.

The Volume Surge

UCLOUD's session volume went from 9.7 million to 55.4 million in one week — displacing DigitalOcean as the top ASN by session volume in GreyNoise data:

Week UCLOUD Sessions DigitalOcean Sessions UCLOUD Rank
Mar 5-11 9,679,761 31,361,945 #3
Mar 12-18 55,384,799 22,709,383 #1
Change +472% -27.6%

Figure 4: Daily session counts showing UCLOUD overtaking DigitalOcean as the top ASN by session volume in GreyNoise data.

The Rotation: Everything Shifted in Seven Days

The ghost fleet wasn't the only change. The entire scanning landscape observed by GreyNoise reshuffled. AS213438, a top ASN the prior week with 10.7 million sessions, disappeared entirely — an abrupt shutoff consistent with infrastructure being decommissioned or rotated.

What declined (source refers to IP geolocation; destination refers to GOG sensor location):

Source (by IP geolocation) Mar 5-11 Mar 12-18 Change
Australia to US 4,109,617 sessions 1,153,593 -71.9%
Netherlands to US 17,886,273 12,952,923 -27.6%
Netherlands to Spain 5,540,230 3,112,579 -43.8%
Canada to US 3,649,150 2,454,528 -32.7%

What appeared (source refers to IP geolocation; destination refers to GOG sensor location):

Source (by IP geolocation) Mar 5-11 Mar 12-18 Change
Hong Kong to US 4,744,912 15,427,214 +225%
Poland to Spain 312,708 8,325,850 +2,563%
Hong Kong to Spain 1,410,537 7,117,338 +405%
Thailand to US 966,313 5,468,241 +466%
Nigeria to US 559,975 2,863,781 +411%
Lithuania to US 1,523,952 5,300,605 +248%
Bulgaria to US 1,496,734 3,444,281 +130%

Figure 5: Week-over-week changes in scanning traffic by source-destination pair, as observed by GreyNoise.

Under the Hood

Cross-referencing GreyNoise observations with Censys internet-wide scan data and VirusTotal reputation data reveals infrastructure patterns not visible from any single source.

Templated deployment across borders.

A cluster on infrastructure geolocating to Germany, registered to a Seychelles entity, shows configurations consistent with deployment from a single VM image. A separate Windows VPS cluster uses IPs geolocating to Bulgaria, Romania, and France across three ASNs with an identical service configuration on each node — scanning infrastructure deployed from a common template.

UCLOUD relay infrastructure.

Censys data reveals purpose-built traffic relay and tunneling software deployed across UCLOUD at a density not typical of legitimate hosting. Repeating non-standard port configurations appear identically across multiple subnets — the signature of a single VM template deployed at scale.

Low reputation detection.

The top scanning IPs are barely flagged:

IP Provider Vendor Detections Notable
109.205.211[.]101 MEVSPACE / Colocatel Inc. (AS201814) 2 of 94 Zero communicating files. 7.97M sessions/week. IPs geolocate to Poland; registered to Colocatel Inc. (Seychelles).
79.124.58[.]146 Tamatiya EOOD (AS50360) 5 of 94 IPs geolocate to Bulgaria. Self-signed SSL cert: localhost.localdomain by "VMware Installer"
91.238.181[.]10 Fbw Networks SAS (AS49434) 7 of 94 IPs geolocate to France. Communicating file: mssecsvr.exe (Win32, first seen 2018). Malicious history predating current activity.

What We Don't Know

GreyNoise cannot determine the purpose of the ghost fleet from GreyNoise data alone. Censys confirms these ASNs are active hosting ecosystems — the spoofable traffic uses source addresses in IP ranges distinct from the legitimate hosted infrastructure. What we can say: 242,666 IPs appeared, almost none completed connections, and the source addresses are unverified.

What Defenders Should Do

  • Detection stacks that don't distinguish spoofable IPs from confirmed scanners may be affected. 242,666 unverified source addresses now exist in observation datasets. Systems that weight activity by IP count without verifying connections should be reviewed.
  • Update blocklists. The sources that dominated scanning the prior week declined or disappeared, replaced by infrastructure geolocating to Hong Kong, Poland, and Germany — all within seven days.
  • Monitor UCLOUD (AS135377). GreyNoise observed multi-protocol scanning activity targeting MySQL (3306), SSH (22), SMB (445), and RDP (3389).
  • Track the ghost fleet ASNs for behavioral changes: AS9294, AS138415, AS55933, AS135097, AS17561, AS45753. If these IPs begin completing TCP handshakes and deploying payloads, the assessment changes.

GreyNoise is not attributing this activity to a named threat actor or state sponsor. The geographic references in this post describe where IPs are registered, not necessarily where the operators are located. Hosting infrastructure is routinely used by actors with no geographic connection to the provider's registration.

GreyNoise Integrates with Google Security Operations to Enhance Detection and Response Capabilities

GreyNoise integration with Google Security Operations enables improved dashboards, detection rules, playbooks, and webhook support

Your SIEM ingests everything. Every port scan, every crawl, every opportunistic spray across the internet. The problem isn't the collection — it's context. Which of those IPs are scanning everyone, and which ones are targeting you?

That's the question GreyNoise answers. We observe over over 800,000 unique IPs daily across 5,000+ sensors in 80+ countries, classifying each as malicious, suspicious, benign, or unknown, and tagging them with 3,000+ behavioral descriptors. Traditional threat feeds add more indicators to investigate. GreyNoise removes the ones that don't matter.

Today, we're announcing a new and improved integration with Google Security Operations — delivering standardized indicator ingestion, pre-built dashboards, YARA-L detection rules, saved searches, response actions, webhook support, and ready-to-deploy playbooks.

What's New: Event Management

New Ingestion Script

The GreyNoise ingestion script is now available in Google Security Operations ingestion-scripts repository — a standardized process for importing threat intelligence indicators into your environment. Deployed as a Google Cloud function, it pulls IP reputation data and GNQL query results from the GreyNoise API and ingests them via the Google Security Operations API. The default configuration focuses on malicious IPs observed in the last 24 hours, but teams can customize the GNQL query to match their threat profile.

New Dashboards

Two interactive dashboards ship with the integration into Google Security Operations:

Indicator Dashboard — 15+ visualization panels covering classification distribution (Malicious, Suspicious, Benign, Unknown), top 10 rankings for organizations, actors, tags, ASNs, categories, operating systems, and source countries, plus CVE distribution, trend analysis, and business service intelligence.

GreyNoise Indicator Dashboard in Google Security Operations

Correlation Dashboard — Shows IOC matches between GreyNoise intelligence and events from your environment, with geolocation mapping, event match trends, classification breakdowns, and top IP indicator rankings.

GreyNoise Correlation Dashboard in Google Security Operations

Indicators broken down by classification

New YARA-L Detection Rules

Three ready-to-deploy rules that start correlating immediately:

  • IP Match — Detects events where a source or principal IP matches a malicious or suspicious GreyNoise indicator, correlating over a 1-hour window.
  • Inbound Network Traffic with ASN Context — High-severity rule monitoring firewall logs for permitted inbound connections from GreyNoise-flagged malicious IPs, enriched with ASN attribution.
  • Brute Force Attack Detection — High-severity rule flagging 5+ blocked login attempts from GreyNoise-flagged IPs within a 15-minute window.

New Saved Searches

Four pre-built UDM queries for investigation workflows:

  • IP Risk & Vulnerability Details — Classification, anonymization signals, CVEs, and activity timelines
  • Indicator Context Summary — Actor attribution, geographic details, organizations, and tags
  • High Risk Indicators — Filters for MALICIOUS or SUSPICIOUS classifications only
  • All Indicator Lookup — Browse all ingested GreyNoise indicators for ad-hoc investigation

IOC Geolocation Overview — mapping matched indicators globally

What's New: Response Workflows

Updated Response Actions (v7.0)

The GreyNoise response integration has been updated to version 7.0 with the full suite of actions:

Action What It Does
IP Lookup Full enrichment — classification, tags, metadata
Quick IP Lookup Fast context check on any IP
IP Timeline Lookup Historical view of scanning behavior over time
Execute GNQL Query Run arbitrary GreyNoise queries within a playbook
Get CVE Details Vulnerability context from exploitation activity
Ping Validate API connectivity

New Webhook Support

A major addition: webhook support for ingesting GreyNoise alerts and event feeds directly into Google Security Operations. Three webhook types are now available:

  • Alert Webhook — Ingests IP, CVE, TAG, and GNQL Query alerts
  • IP Change Webhook — Tracks classification changes in real time
  • CVE/Tag Webhook — Monitors CVE spikes, status changes, vendor activity, and tag spikes

New Playbooks

Pre-built playbooks ship with the integration, providing ready-made automation workflows that teams can deploy or customize. Combined with the webhook connectors and the Generate Alert from GreyNoise GNQL connector, security teams can build end-to-end automated triage pipelines.

On-demand IP Lookup 

How It Works Together

  • 1. Ingest — The event management integration continuously pulls GreyNoise indicators into Google Security Operations with fresh scanner data.
  • 2. Detect — YARA-L detection rules flag events that correlate with known scanners. Dashboards provide visual context.
  • 3. Investigate — Saved searches surface IP risk details, actor attribution, and CVE context without writing queries.
  • 4. Respond — Response playbooks enrich flagged IPs automatically. Mass scanners get deprioritized. Targeted activity escalates for review.

Webhooks close the loop by pushing GreyNoise alerts — including classification changes and CVE spikes — directly into Google Securioty Operations for quick action.

Who Has Access

This integration is available to any joint Google Security Operations customer with a GreyNoise API key. No additional licensing required — just configure and go.

Learn More and Get Started

Ready to bring GreyNoise intelligence into your Google Security Operations environment? Learn more here:

GreyNoise Intelligence Is Available Across the CrowdStrike Falcon Platform

Every SOC analyst knows the feeling: another morning, another queue of hundreds of alerts, and the gnawing question of which ones actually matter. The volume of internet background noise — automated scanners, research probes, vulnerability crawlers — hasn’t slowed down. If anything, it’s accelerating. And as adversaries adopt AI to move faster, the cost of chasing the wrong signals isn’t just frustrating — it’s dangerous.

That’s the problem GreyNoise was built to address. We operate one of the largest passive sensor networks on the internet — more than 5,000 sensors across 80 countries, analyzing up to one billion sessions per day and tracking over 50 million IPs. That scale lets us classify internet-wide scanning and reconnaissance activity with confidence: which IPs are known benign scanners, which are actively malicious, and which are unknown — meaning we haven’t observed them scanning the internet indiscriminately.

That classification data is now available across the CrowdStrike Falcon platform — in Next-Gen SIEM, Falcon Fusion SOAR, and the agentic workflows that are defining the next era of security operations.

GreyNoise Intelligence Across CrowdStrike Falcon

For teams running Falcon, GreyNoise intelligence is operationalized across three integrated capabilities — inline investigation context in Next-Gen SIEM, automated enrichment and response in Falcon Fusion SOAR, and agentic collaboration through Charlotte AI.

Falcon Next-Gen SIEM: GreyNoise Classification Inside Your Existing Queries

The GreyNoise Foundry App — available directly on the CrowdStrike Marketplace — is the operational core of the integration. Once installed, it automatically imports a fresh GreyNoise indicator lookup file into Next-Gen SIEM every day. No manual feed management. No stale data.

That lookup file contains GreyNoise’s full dataset of classified IPs — benign scanners, malicious actors, CVE-targeting sources, and tagged threat infrastructure. Inside Next-Gen SIEM, analysts use the match() function to incorporate that data directly into their searches and analytics. GreyNoise classification columns — classification, observed activity, exploited CVEs — surface right alongside event data in the query view, with no pivot to an external tool required.

Detections tied to IPs that GreyNoise has identified as active exploit sources or malicious infrastructure stand out. Teams can build correlation rules and dashboards that weight GreyNoise-validated threats higher. And IPs that GreyNoise has classified as benign — known research scanners, internet measurement services, well-documented security vendors — carry that context right in the query results, giving analysts the information they need to make confident triage decisions.

The Foundry App ships with a pre-built app template containing GreyNoise threat intelligence actions, ready to deploy in Foundry and extend into Fusion SOAR workflows.

Falcon Fusion SOAR: Automated Enrichment and Response

Knowing an IP is malicious is useful. Acting on that intelligence automatically is where the efficiency gain lives.

The GreyNoise Foundry App includes a native Falcon Fusion SOAR integration that puts GreyNoise enrichment directly into workflow logic. Security teams can build — or extend — automated playbooks that take action based on GreyNoise IP context:

  • Alert on malicious IPs — trigger high-priority notifications when GreyNoise identifies adversary activity at the perimeter
  • Prioritize vulnerability response — surface CVE exploitation data to inform which vulnerabilities need immediate patching attention
  • Initiate threat hunts — automatically kick off hunt workflows when GreyNoise identifies coordinated scanning tied to known threat infrastructure
  • Automate blocking or containment — close the loop on confirmed malicious IPs

GreyNoise’s benign classification is particularly valuable here. Because GreyNoise classifies known-good IPs — security researchers, CDN health checks, legitimate vulnerability scanners — SOAR workflows have a higher-confidence basis for automated routing decisions. That confidence is grounded in what our sensor network directly observes, not aggregated from third-party sources.

Charlotte AI: GreyNoise as a Trusted Ecosystem Participant

CrowdStrike’s blog on building an agentic security workforce names GreyNoise among the trusted ecosystem participants supported in Charlotte AI’s Agentic Response Collaboration capability — alongside Corelight, ExtraHop, Proofpoint, Google, Abnormal AI, and Zscaler. These integrations provide what CrowdStrike describes as “deep cross-domain context to drive faster, more accurate analysis.”

Charlotte AI’s use of ecosystem data is still maturing, and we’ll share more as it develops. But the direction is clear: as agentic workflows become a core part of how SOC investigations run, GreyNoise intelligence can be part of the reasoning loop.

Here’s what that looks like in practice. An alert fires on a suspicious external IP. Charlotte AI’s Detection Triage Agent is working the case. As part of its investigation, GreyNoise context is available: Is this IP part of a known mass scanner campaign? Has it been observed exploiting the specific vulnerability that generated the alert? Is it tied to active threat infrastructure? That intelligence informs the agent’s triage decision — contributing internet-wide scanning context to a process that already draws from endpoint, identity, and cloud telemetry.

Charlotte AI’s agentic response can trigger workflows in Falcon Fusion SOAR, which means GreyNoise intelligence already available in your SOAR playbooks carries naturally into AI-driven triage. CrowdStrike’s mission-ready agents — covering detection triage, malware analysis, exposure prioritization, and threat hunting — are trained on years of expert decisions from Falcon Complete analysts. GreyNoise’s classification data adds internet-wide reconnaissance context to those workflows.

What Falcon Users Get

GreyNoise intelligence across the Falcon platform produces three specific outcomes:

  • Higher-confidence triage — GreyNoise classification gives analysts a clear signal on which external IPs are known internet scanners and which warrant deeper investigation
  • Contextualized alerts — every IP-based detection carries GreyNoise behavior, classification, and CVE context from the moment it fires
  • Faster investigation and response — inline enrichment and automated SOAR workflows compress the time from alert to action
  • Prioritized vulnerability response — CVE exploitation intelligence from GreyNoise’s sensor network informs which vulnerabilities are being actively targeted right now

Getting Started

The GreyNoise Foundry App is available on the CrowdStrike Marketplace for Falcon Next-Gen SIEM and Falcon Insight XDR customers. Installation takes minutes, and the daily automated indicator import requires no ongoing maintenance.

Install the GreyNoise Foundry App on the CrowdStrike Marketplace

Read the technical integration documentation

Learn more about GreyNoise

Active Reconnaissance Campaign Targets SonicWall Firewalls Through Commercial Proxy Infrastructure

GreyNoise observed 84,142 scanning sessions targeting SonicWall SonicOS infrastructure between February 22 and February 25, 2026. The activity originated from 4,305 unique IP addresses across 20 autonomous systems, with three operationally distinct infrastructure clusters executing coordinated VPN enumeration. Ninety-two percent of sessions probed a single API endpoint to determine whether SSL VPN is enabled — the prerequisite check before credential attacks. A commercial proxy service delivered 32% of campaign volume through 4,102 rotating exit IPs in two surgical bursts totaling 16 hours. CVE exploitation was negligible, confirming this as systematic attack surface mapping.

Why This Matters

SonicWall SSL VPN is one of the most documented initial access vectors for ransomware. Akira and Fog ransomware groups have repeatedly demonstrated that compromised SonicWall VPN credentials lead to full encryption in under four hours — with dwell times as short as 55 minutes. Five of seven SonicWall CVEs relevant to this attack surface appear in CISA's Known Exploited Vulnerabilities catalog, with four having documented ransomware use. The reconnaissance GreyNoise observed is the precursor phase — systematic target mapping that precedes exploitation.

Since March 2023, Akira alone has compromised at least 250 organizations and generated an estimated $244 million in ransomware proceeds, with 75% of SonicWall VPN intrusions attributed to Akira and 25% to Fog. More than 430,000 SonicWall firewalls are publicly exposed on the internet, with over 25,000 SSL VPN devices vulnerable to critical flaws and 20,000 running firmware that is no longer supported.

This is not the first time GreyNoise has observed this pattern. In December 2025, GreyNoise documented a coordinated credential campaign targeting both Palo Alto and SonicWall VPN infrastructure across 9 million sessions from more than 7,000 IPs, sharing identical client fingerprints across both vendors. The February 2026 campaign represents a continuation and intensification of VPN-focused reconnaissance.

Key Takeaways

  • 84,142 sessions from 4,305 IPs in four days — Coordinated reconnaissance targeting SonicWall VPN enumeration and credential testing endpoints indicates systematic attack surface mapping
  • 92% of sessions probed a single API endpoint — The VPN status check determines which devices have SSL VPN active, creating a target list for future credential attacks
  • 32% of volume routed through a commercial proxy service — 4,102 exit IPs delivered 27,119 sessions in two surgical bursts, averaging 6.6 sessions per IP to evade rate-limiting
  • Multi-vendor VPN reconnaissance — The Netherlands scanning cluster simultaneously targets SonicWall and Cisco ASA devices, indicating a broader VPN mapping operation
  • Reconnaissance dominates — 92% of sessions targeted a single VPN status-check endpoint, confirming systematic target mapping rather than active exploitation
  • Defenders should act now — Restrict management interface access, enforce MFA on SSL VPN, and patch CVE-2024-53704 (CVSS 9.8, CISA KEV) before reconnaissance converts to exploitation

What GreyNoise Observed

Campaign Timeline

The campaign exhibited four distinct bursts separated by a ∼31-hour low-activity period, with a persistent credential-testing baseline running continuously underneath.

Burst 1 — Initial Scan Wave (Feb 22, 00:00–19:00 UTC): The campaign opened with a 19-hour scanning wave peaking at 3,272 sessions per hour. This burst combined proxy infrastructure with the Netherlands scanning cluster, totaling 30,952 sessions on the first day.

Low-Activity Period (Feb 22 21:00 – Feb 24 04:00 UTC, ∼31 hours): Session volume dropped to a 54–90 session/hour baseline — exclusively the persistent NetExtender credential testing cluster operating on autopilot.

Burst 2 — Proxy Resurgence (Feb 24, 04:00–12:00 UTC): The proxy infrastructure reactivated for a focused 8-hour window, delivering 17,991 sessions through rotating exit IPs. Per-IP volume remained extremely low (average 6.6 sessions, maximum 13), consistent with a proxy service rotating exit nodes.

Burst 3 — Peak Hour (Feb 24, 15:00–17:00 UTC): 7,374 sessions in the 15:00 UTC hour — the single highest hourly count of the entire campaign — followed by 5,484 in the 16:00 hour. This burst originated from the Netherlands scanning cluster, not the proxy pool.

Burst 4 — Final Surge (Feb 25, 08:00–13:00 UTC): A final burst peaked at 5,899 sessions in the 11:00 UTC hour, indicating ongoing orchestration.

Date Sessions
February 22 30,952
February 23 1,639 (baseline only)
February 24 32,616 (peak — three bursts)
February 25 18,935 (partial day)

The dramatic February 23 lull — a 95% drop from the preceding day — is operationally significant. The scanning infrastructure did not fail; the persistent NetExtender cluster continued uninterrupted at its normal rate. The pause suggests deliberate operational scheduling.

What Is Being Targeted

Two SonicWall-specific paths dominate the campaign, accounting for over 99.5% of all sessions:

Target Sessions % Purpose
SonicOS REST API — VPN status check 77,253 91.8% Determines whether SSL VPN is enabled
NetExtender VPN client login endpoint 6,629 7.9% Credential testing via legitimate VPN client
Other management paths 260 0.3% Various admin endpoints

The overwhelming concentration on the VPN status API endpoint reveals the campaign’s objective: building a comprehensive list of SonicWall devices with active SSL VPN. This is a prerequisite for credential attacks — identifying which devices are worth targeting before deploying more expensive proxy resources for login testing.

Four Infrastructure Clusters

Cluster 1: Netherlands VPN Hunters (28% of Campaign)

Six IPs within a single Ukrainian-registered autonomous system (AS211736) operating from Amsterdam-based infrastructure delivered 23,794 sessions. These IPs run dual-vector scanning: VPN status enumeration paired with Cisco ASA reconnaissance, indicating a multi-vendor VPN mapping operation.

Censys infrastructure profiling revealed these nodes run identical software stacks. All share a single HASSH fingerprint, confirming deployment from a common provisioning template. Four of the six expose HTTP services on ports 7001–7003 with identical bare-minimum 404 responses — consistent with a custom scanning framework spawning worker threads.

IP ASN Sessions Also Scans
88[.]210[.]63[.]78 AS211736 4,669 Cisco ASA
185[.]156[.]73[.]19 AS211736 4,620 Cisco ASA
185[.]156[.]73[.]73 AS211736 4,491 Cisco ASA
88[.]210[.]63[.]77 AS211736 4,340 Cisco ASA
185[.]156[.]73[.]31 AS211736 4,333 Cisco ASA
88[.]210[.]63[.]79 AS211736 1,341 Cisco ASA

Cluster 2: Commercial Proxy Spray (32% of Campaign)

27,119 sessions originated from 4,102 IP addresses in the 154[.]208[.]64[.]0/21 range, transiting through AS3257 (GTT Communications) from Canadian hosting infrastructure.

The proxy service — ByteZero (bytezero[.]io) — markets itself as offering 100+ million IPs across 150+ countries for web scraping and data collection. The scanning traffic originates from ByteZero’s paying customers, not the proxy infrastructure itself. ByteZero is the anonymization layer enabling the activity.

The proxy usage was surgical — concentrated in two primary windows:

Window Duration Sessions
Feb 22, 00:00–06:00 UTC 7 hours 8,019
Feb 24, 04:00–12:00 UTC 9 hours 17,991

A critical detail: ByteZero’s customer management platform went offline in early December 2025. The proxy nodes have continued operating for approximately three months without active abuse mitigation. This directly explains the unchecked scanning volume.

Cluster 3: The Mega-Scanner (22% of Campaign)

A single IP — 130[.]12[.]180[.]29 on AS202412 (Omegatech, registered in the Seychelles), geolocating to Germany — generated 18,763 sessions. This IP scanned across 20+ destination ports including non-standard ports (6666, 7777, 7443, 9443), cycling through 26 different browser user agents to evade basic fingerprinting.

Cluster 4: NetExtender Persistent (8% of Campaign)

156 IPs across four dedicated ranges maintain continuous credential testing at 54–72 sessions per hour against the NetExtender VPN login endpoint. This cluster uses a legitimate SonicWall VPN client identifier and never stops — it ran uninterrupted through the February 23 low-activity period. Total: 6,629 sessions over four days.

Fingerprint Analysis

A single HTTP fingerprint was present in 58,510 sessions — nearly 70% of the entire campaign. The associated user agent presents as a modern browser (Chrome 119 on Linux) but is paired with HTTP/1.0, a protocol version that legitimate Chrome browsers never use. This mismatch is a reliable, high-confidence indicator of automated scanning tooling.

Fingerprint Sessions % Behavior
4-header GET, HTTP/1.0, Chrome UA 58,510 69.5% NL cluster + proxy (VPN enum)
17-header GET, HTTP/1.1, rotating UAs 18,763 22.3% Mega-scanner
6-header POST, HTTP/1.1, NetExtender 6,629 7.9% Credential testing

Exploitation Assessment

Despite the reconnaissance volume, the campaign's behavioral profile is overwhelmingly pre-exploitation. 92% of sessions queried a single API endpoint to determine VPN status — a prerequisite check, not an exploit. GreyNoise maintains CVE-specific detection tags for six of the seven CVEs below; CVE-2024-40766 does not currently have a detection tag.

CVE CVSS CISA KEV Ransomware Use Campaign Sessions
CVE-2024-53704 9.8 Yes Yes 5
CVE-2024-40766 9.8 Yes Yes (Akira, Fog) No tag
CVE-2022-22274 9.8 No No 9*
CVE-2023-0656 7.5 No No 9*
CVE-2021-20028 9.8 Yes Yes 8
CVE-2024-38475 9.1 Yes Unknown 6
CVE-2019-7481 7.5 Yes Yes 6

*CVE-2022-22274 and CVE-2023-0656 are detected by the same GreyNoise tag ("SonicOS RCE Attempt"). The 9 campaign sessions apply to both CVEs collectively.

Four of the five CISA KEV entries have documented ransomware use. The behavioral profile of this campaign — 92% concentrated on a single VPN status-check endpoint — is consistent with pre-exploitation reconnaissance rather than active exploitation. The targets identified during this mapping phase are likely to face exploitation attempts in the days and weeks ahead.

Strategic Implications

The use of commercial proxy services for VPN reconnaissance represents a maturation of the threat. Unlike botnets with fixed infrastructure, proxy services provide rotating datacenter IP addresses that are difficult to distinguish from legitimate traffic. The low per-IP session volume — averaging 6.6 sessions per exit node — is calibrated to evade rate-limiting and reputation-based blocking. Static blocklists cannot keep pace with infrastructure that rotates thousands of IPs within a single scan window.

The headless state of the proxy service — operating for three months without active abuse oversight after its management platform went offline — highlights a structural gap in the proxy ecosystem. When proxy providers lose the ability or incentive to police their customers’ traffic, their infrastructure becomes functionally equivalent to bullet-proof hosting.

This pattern is accelerating. In January 2026, Google disrupted IPIDEA — a residential proxy network used by over 550 threat groups including nation-state APTs — for credential stuffing and C2 obfuscation. The Shadowserver Foundation has tracked a separate campaign using 2.8 million IPs daily to brute-force VPN login portals. The proxy ecosystem has become the primary enabler of credential-based initial access.

Organizations running SonicWall firewalls should treat this reconnaissance as an early warning. The documented Akira ransomware kill chain begins with compromised SonicWall VPN credentials and achieves encryption in under four hours. SonicWall itself has confirmed that recent intrusions resulted from password reuse combined with CVE exploitation. The gap between the reconnaissance GreyNoise is observing and the exploitation that follows may be shorter than many organizations’ patching cycles.

Check If Your SonicWall Was Targeted (5 Minutes)

Step 1 — Check your logs (2 minutes). Search firewall logs for external requests to these paths between February 22–25:

  • /api/sonicos/is-sslvpn-enabled (VPN status check)
  • /sonicui/7/login/ (management interface)
  • /cgi-bin/userLogin (VPN credential testing)

Step 2 — Check active VPN sessions (1 minute). Navigate to NETWORK | SSL VPN > Status in SonicOS 7.x. Look for sessions from IP addresses outside your user base, particularly from hosting or VPS providers.

Step 3 — Verify firmware and MFA (2 minutes). Confirm your SonicOS firmware is patched against CVE-2024-53704 (versions at or below 7.1.1-7058, 7.1.2-7019, or 8.0.0-8035 are vulnerable). Confirm MFA is enabled for all SSL VPN users.

If your SonicWall was probed and you are running end-of-life SRA appliances, disconnect them immediately — CVE-2021-20028 and CVE-2019-7481 have no patches available.

Recommendations

For Security Leadership:

  • Audit SonicWall management interface exposure — administrative endpoints should never be internet-accessible
  • Verify MFA is enforced on all SSL VPN users — credential stuffing is rendered ineffective by MFA
  • Evaluate dynamic blocklists to address the IP rotation that makes static lists ineffective against proxy-based campaigns
  • Treat VPN infrastructure as a priority patching tier — the reconnaissance-to-exploitation gap is narrowing

For Security Operations:

  • Restrict access to /sonicui/7/login/ and /api/sonicos/ paths to trusted management IPs only
  • Monitor for HTTP/1.0 requests paired with modern browser user agents — this combination is a high-confidence indicator of automated scanning
  • Block identified scanning infrastructure at the perimeter:
  • 154[.]208[.]64[.]0/21 (proxy exit nodes)
  • 185[.]177[.]72[.]0/24 (bullet-proof hosting)
  • 185[.]156[.]73[.]0/24 and 88[.]210[.]63[.]0/24 (scanner fleet)
  • 204[.]76[.]203[.]0/24 (scanning with credential collection indicators)

For SonicWall Administrators:

  • Patch SonicOS against CVE-2024-53704 (CVSS 9.8, CISA KEV) — SonicWall advisory SNWLID-2025-0003
  • Reset all local user account passwords, especially those carried over during Gen 6 to Gen 7 migrations
  • Decommission end-of-life SRA appliances — no patches are available for CVE-2021-20028 or CVE-2019-7481
  • Enable login attempt lockout and password complexity enforcement (SonicOS 7.3+)
  • SonicWall administrators running SonicOS 7.3.2 or NSM SaaS also have access to the Credential Auditor feature, which provides visibility into credential sprawl and reuse across the firewall environment
  • Enable Geo-IP filtering and Botnet Protection on the firewall

View real-time GreyNoise data on SonicWall activity:

2026 GreyNoise State of the Edge Report: Where Attacks Concentrate and Defenses Fall Short

GreyNoise analyzed 2.97 billion sessions over 162 days in H2 2025, and the patterns reveal where edge defenses hold up — and where they fall short. The data exposes specific concentration points in VPN targeting, infrastructure sourcing, and exploitation behavior that challenge conventional defensive assumptions.

What the Data Shows

Across the GreyNoise Global Observation Grid, several findings challenge conventional assumptions about where attacks concentrate:

Palo Alto GlobalProtect received 16.7 million sessions — more than 3.5x Cisco and Fortinet combined. This disproportionate concentration warrants investigation, though direct market share comparison was not part of this analysis. GlobalProtect deployments provide direct network access if compromised, making them high-value targets.

52% of remote code execution attempts came from IPs with no prior history in GreyNoise data. For remote code execution — widely considered the highest-severity exploitation category — GreyNoise had no prior record of more than half the attacking IPs. That means attackers are spinning up and burning through fresh infrastructure faster than any static threat feed can catalog it — and GreyNoise detected these IPs the moment they first appeared, before any other source had them.

Pre-2015 CVEs generated 7.3 million sessions — 4x more than 2023-2024 CVEs combined. One vulnerability — CVE-1999-0526, a 26-year-old X Server information disclosure — accounts for the majority. Even excluding it, Shellshock and PHP-CGI continue generating measurable traffic a decade later. Patching programs optimized for recency leave decade-old exposure unaddressed.

300,000 residential IPs participated in a single credential-spraying campaign — 73% classified as residential by ISP categorization, with no prior GreyNoise history. Geographic blocking, reputation scoring, rate limiting: would have limited effectiveness against this traffic pattern.

91,403 sessions targeted AI/LLM infrastructure. The same types of automated scanning patterns hitting VPNs and routers are now cataloging exposed LLM endpoints.

Why This Matters

The Verizon 2025 DBIR documented an 8x increase in edge device exploitation in a single year — edge vulnerabilities jumped from 3% to 22% of all vulnerability exploitation breaches. Mandiant M-Trends 2025 found the top four most frequently exploited vulnerabilities were all in edge devices — Palo Alto PAN-OS, Ivanti Connect Secure, Ivanti Policy Secure, and Fortinet FortiClient EMS. CISA issued Binding Operational Directive 26-02, requiring federal agencies to address end-of-support edge devices. The GreyNoise data is consistent with all of it — and quantifies the scale.

This isn't a theoretical shift. If your organization runs internet-facing VPN appliances, routers, or AI infrastructure, this traffic is reaching you.

What's Inside the Report

The full report includes:

  • Vendor-by-vendor breakdown of VPN, router, and firewall targeting
  • Infrastructure concentration analysis — how a single provider accounted for 14% of all observed sessions
  • The residential botnet that grew from 2,000 to 300,000 IPs in 72 days
  • CVE age distribution showing where exploitation actually concentrates versus where patching effort concentrates
  • Infrastructure freshness analysis across attack severity categories
  • An emerging campaign targeting AI/LLM inference servers
  • Actionable recommendations for security leadership, operations, and vulnerability management

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