Grey Noise

Learn how GreyNoise Feeds enable real-time, event-driven threat intelligence that eliminates polling delays—helping defenders react instantly to new exploits, IP threats, and zero-day activity.

On October 3, 2025, GreyNoise observed a ~500% increase in IPs scanning Palo Alto Networks login portals, the highest level recorded in the past 90 days. The activity was highly targeted and involved multiple, potentially coordinated scanning clusters.

GreyNoise observed a sharp one-day surge of exploitation attempts targeting CVE-2021-43798 — a Grafana path traversal vulnerability that enables arbitrary file reads. All observed IPs are classified as malicious.

GreyNoise MCP Server is now available, enabling AI agents compatible with the Model Context Protocol (MCP) to efficiently consume GreyNoise intelligence, enhancing data-driven security insights.

GreyNoise observed two scanning surges against Cisco Adaptive Security Appliance (ASA) devices in late August including more than 25,000 unique IPs in a single burst. This activity represents a significant elevation above baseline, typically registering at less than 500 IPs per day. 

On August 21, GreyNoise observed a sharp surge in scanning against Microsoft Remote Desktop (RDP) services. The wave’s aim was clear: test for timing flaws that reveal valid usernames, laying the groundwork for credential-based intrusions.

On August 3rd, 2025 GreyNoise observed a significant spike in brute-force traffic targeting Fortinet SSL VPNs. Over 780 unique IPs triggered our Fortinet SSL VPN Bruteforcer tag in a single day — the highest single-day volume seen on this tag in recent months.

What if defenders could prepare for new vulnerabilities before they’re disclosed? GreyNoise’s latest research reveals that spikes in attacker activity often precede the disclosure of new CVEs — typically within six weeks. These findings shed light on a narrow but reliable early warning signal, giving security teams a critical window to harden defenses, monitor closely, and act ahead of emerging threats.

Close the speed gap in your security. GreyNoise unveils new real-time dynamic blocklists, push-based threat intelligence feeds, and SOAR integrations to help defenders detect, block, and respond to automated attacks faster than ever.

A spike in botnet traffic from a single utility in a rural part of New Mexico led to the discovery of a global botnet. Explore how human-led, AI-powered analysis exposed compromised devices, uncovered attack patterns, and why defenders should take note.

A vulnerability disclosed in May 2025, CVE-2025-48927, affects certain deployments of TeleMessageTM SGNL. If exposed, this endpoint can return a full snapshot of heap memory which may include plaintext usernames, passwords, and other sensitive data.

GreyNoise has observed active exploitation attempts against CVE-2025-5777 (CitrixBleed 2), a memory overread vulnerability in Citrix NetScaler. Exploitation began on June 23 — nearly two weeks before a public proof-of-concept was released on July 4. 

GreyNoise has identified a previously untracked variant of a scraper botnet, detectable through a globally unique network fingerprint. To detect it, GreyNoise analysts created a signature using JA4+, the suite of JA4 signatures used to fingerprint network traffic.

GreyNoise has identified a notable surge in scanning activity targeting MOVEit Transfer systems, beginning on May 27, 2025. Prior to this date, scanning was minimal — typically fewer than 10 IPs observed per day. But on May 27, that number spiked to over 100 unique IPs, followed by 319 IPs on May 29. 

‍On June 16, GreyNoise observed exploit attempts targeting CVE-2023-28771 — a remote code execution vulnerability affecting Zyxel Internet Key Exchange (IKE) packet decoders over UDP port 500.

GreyNoise recently observed a coordinated spike in malicious activity against Apache Tomcat Manager interfaces. On June 5, 2025, two GreyNoise tags — Tomcat Manager Brute Force Attempt and Tomcat Manager Login Attempt — registered well above baseline volumes, indicating a deliberate attempt to identify and access exposed Tomcat services at scale.

GreyNoise uncovers a stealth campaign exploiting ASUS routers, enabling persistent backdoor access via CVE-2023-39780 and unpatched techniques. Learn how attackers evade detection, how GreyNoise discovered it with AI-powered tooling, and what defenders need to know.

On May 8, GreyNoise observed a highly coordinated reconnaissance campaign launched by 251 malicious IP addresses, all geolocated to Japan and hosted by Amazon AWS. The infrastructure and execution suggest centralized planning.

Two critical Ivanti zero-days (CVE-2025-4427 and CVE-2025-4428) are now being actively exploited after a surge in scanning activity last month. When chained together, these vulnerabilities enable unauthenticated remote code execution on Ivanti Endpoint Manager Mobile systems.

Edge vulnerabilities are a critical and growing threat. The 2025 DBIR reveals an eightfold surge in exploitation, yet many remain unpatched despite immediate risk.