Detections

Explore public detection logic contributed by the community across SIEM and rule languages.

303 detections

This rule detects potential SSH brute force attacks by identifying multiple failed password attempts from a single source IP address to a specific computer within a 5-minute window. It specifically looks for 'Failed password' messages in syslog entries from the 'sshd' process.
avatar
Ankit Mehta@Secvyn
Bharat Cyber Guardians
4 months ago
207
Detects unauthorized file write or rename operations targeting core OpenSSH binary and library paths, excluding known package manager activities. This behavior is indicative of an adversary replacing legitimate system binaries to create a trojanized version of OpenSSH, as observed in the Velvet Ant 'Operation Highland' campaign, used to harvest credentials and log SSH sessions.
avatar
Ibrahim Saud@tektrix
avatar
Detections.ai Community
4 months ago
007
Detects suspicious file creation activities by system authentication processes (e.g., sshd, su, sudo, PAM) in known staging directories (/tmp, /var/tmp, /dev/shm) or SSH configuration paths. The rule looks for hidden files or files with specific extensions (.log, .dat, .bak) often associated with malicious backdoored components used to intercept and store credentials in plaintext.
avatar
Ibrahim Saud@tektrix
avatar
Detections.ai Community
4 months ago
107
Detects instances where the Claude Code AI agent or its subprocesses are used to establish persistence. This is achieved by monitoring for crontab modifications or direct writes to SSH authorized_keys files, which are common indicators of post-exploitation activity following an Axiom-style indirect prompt injection.
avatar
Ethan Andrews@eandrews
avatar
Federal Signal Detections
4 months ago
109
Detects anomalous SSH connections originating from internal network appliances or DMZ-segment devices (e.g., storage, firewalls) to multiple internal network hosts. This behavior is indicative of lateral movement or SSH tunneling as observed in the VerdantBamboo BRICKSTORM campaign, where edge devices are leveraged as pivot points.
avatar
Ibrahim Saud@tektrix
avatar
Detections.ai Community
4 months ago
206
This rule detects the installation, service configuration, and key management activities associated with the OpenSSH server on both Windows and Linux environments. It monitors for commands related to installing OpenSSH capabilities or packages, starting the sshd service, modifying SSH registry keys on Windows, creating or modifying configuration files (sshd_config), and updating authorized_keys files. It also flags inbound network connections to non-standard or default SSH ports originating from external IP ranges.
avatar
Ibrahim Saud@tektrix
avatar
Detections.ai Community
4 months ago
006
Detects successful SSH authentication to administrative accounts ('vmanage-admin' or 'admin') on Cisco Catalyst SD-WAN Manager (vManage) devices originating from IP addresses associated with the threat actor UAT-8616. This activity relates to exploits targeting CVE-2026-20127 and CVE-2026-20182 for unauthorized access via authentication bypass or certificate abuse.
avatar
Ibrahim Saud@tektrix
avatar
Detections.ai Community
4 months ago
107
This rule detects two potentially malicious activities related to SSH: first, specific utilities (e.g., luserput, blacklist, ssh) initiating outbound connections to internal network CIDR ranges over port 22, which may indicate lateral movement; second, the creation or modification of the .ssh/authorized_keys file, which is a common technique for establishing persistence or unauthorized access.
avatar
Ibrahim Saud@tektrix
avatar
Detections.ai Community
4 months ago
205
Detects the unauthorized installation and service configuration of OpenSSH Server on Windows workstations. This technique is used to establish persistent, redundant backdoor access, as observed in Operation Poisson, where adversaries deploy it to maintain access alongside other tools like Tailscale.
avatar
Ibrahim Saud@tektrix
avatar
Detections.ai Community
4 months ago
205
Detects anomalous SSH daemon (sshd) activity characterized by the installation or execution of a non-standard sshd binary (often located in /tmp or /var/tmp) or the execution of sshd with suspicious command-line arguments (custom ports or custom configuration files), followed by modifications to the authorized_keys file. This behavior is indicative of unauthorized persistence or backdoor access.
avatar
Ibrahim Saud@tektrix
avatar
Detections.ai Community
4 months ago
105
This rule detects successful SSH login attempts from external IP addresses (not within common private IP ranges). It specifically looks for 'Accepted' messages in syslog from the 'sshd' process and filters out internal source IPs.
avatar
Ankit Mehta@Secvyn
Bharat Cyber Guardians
4 months ago
305
Detects multiple failed SSH authentication attempts against a server from a single source within a short timeframe, which is indicative of a brute force password attack.
avatar
Ankit Mehta@Secvyn
avatar
Detections.ai Community
4 months ago
005
This rule detects potential SSH brute force attacks by identifying high-frequency authentication failures from sshd logs (more than 10 failures in 5 minutes) and rapid, potentially automated connection attempts on port 22 (more than 20 connections in 1 minute) originating from the same source IP on Linux systems.
avatar
Ankit Mehta@Secvyn
avatar
Detections.ai Community
4 months ago
005
Detects administrative commands (e.g., showing running configuration, copying startup configuration, or accessing enable secret) executed via SSH or Telnet on network devices from non-baseline management IP addresses.
avatar
Ankit Mehta@Secvyn
Bharat Cyber Guardians
4 months ago
104
Detects signs of unauthorized persistence establishment on Cisco SD-WAN nodes (vManage, vSmart, vBond). This rule monitors for modifications to authorized_keys files, creation of suspicious local accounts (e.g., troot), and configuration changes to permit root SSH logins, which are known tactics used to maintain persistent backdoor access following exploitation.
avatar
Ibrahim Saud@tektrix
avatar
Detections.ai Community
4 months ago
005
Detects unauthorized access and command execution associated with MSP service accounts. The rule triggers on successful SSH authentication using specific service account names (e.g., egnyteservice) followed by the execution of interactive shells under those same service account contexts, which is indicative of potential lateral movement or compromise in downstream environments.
avatar
Ibrahim Saud@tektrix
avatar
Detections.ai Community
4 months ago
103
Detects multiple failed SSH login attempts from a single source IP address, indicating a potential brute force attack. The rule identifies 'Invalid user' or 'Failed password' messages in syslog from the 'sshd' process and groups them by source IP and time to count unique attempted users and total attempts. A threshold of more than 5 attempted users from a single source IP within a 10-minute window triggers an alert.
avatar
Ankit Mehta@Secvyn
Bharat Cyber Guardians
4 months ago
103
This rule detects instances where common web server processes (e.g., httpd, nginx) or system utility services (e.g., sshd, crond, dropbear) spawn shell processes like bash, sh, or ash. This activity is a classic indicator of potential remote command execution (RCE) via web application exploits or the abuse of legitimate system services to run arbitrary commands.
avatar
Ibrahim Saud@tektrix
avatar
Detections.ai Community
4 months ago
003
This rule detects successful SSH login attempts from external IP addresses (not within common private IP ranges). It specifically looks for 'Accepted' messages in syslog from the 'sshd' process and filters out internal source IPs.
avatar
Ankit Mehta@Secvyn
Bharat Cyber Guardians
4 months ago
204
This rule detects potential SSH brute force attacks by monitoring syslog for multiple failed SSH login attempts, connection closures, or invalid user attempts from a single source IP address within a short time frame. It specifically looks for keywords like 'error', 'Connection closed', 'authentication failure', and 'invalid user' in SSHD logs.
avatar
Ankit Mehta@Secvyn
Bharat Cyber Guardians
4 months ago
104
Detects unauthorized modifications to SSH 'authorized_keys' files or the '/etc/ssh/sshd_config' configuration file on Linux systems. These actions can be used for persistent access (key injection) or to weaken SSH security controls (e.g., enabling root login) and are typical indicators of account manipulation or compromise.
avatar
Ankit Mehta@Secvyn
Bharat Cyber Guardians
4 months ago
003
Page 4 of 15