Detections

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

1,052 detections

Detects logs clearing attempts on Linux systems via utilities such as 'rm', 'rmdir', 'shred', and 'unlink' targeting log files and directories.
Adversaries often try to clear logs to cover their tracks after performing malicious activities.
avatar
SigmaHQ Detections@sigmaHQ
avatar
SigmaHQ
6 months ago
000
Detects specific commands commonly used to remove or empty the syslog. Which is a technique often used by attacker as a method to hide their tracks
avatar
SigmaHQ Detections@sigmaHQ
avatar
SigmaHQ
6 months ago
000
Detects usage of the 'crontab' utility to remove the current crontab.
This is a common occurrence where cryptocurrency miners compete against each other by removing traces of other miners to hijack the maximum amount of resources possible
avatar
SigmaHQ Detections@sigmaHQ
avatar
SigmaHQ
6 months ago
000
Detects the injection of code by overwriting the memory map of a Linux process using the "dd" Linux command.
avatar
SigmaHQ Detections@sigmaHQ
avatar
SigmaHQ
6 months ago
000
Detects the doas tool execution in linux host platform. This utility tool allow standard users to perform tasks as root, the same way sudo does.
avatar
SigmaHQ Detections@sigmaHQ
avatar
SigmaHQ
6 months ago
000
Detects installation of suspicious packages using system installation utilities
avatar
SigmaHQ Detections@sigmaHQ
avatar
SigmaHQ
6 months ago
000
Detect use of iptables to flush all firewall rules, tables and chains and allow all network traffic
avatar
SigmaHQ Detections@sigmaHQ
avatar
SigmaHQ
6 months ago
000
Detects setting proxy configuration
avatar
SigmaHQ Detections@sigmaHQ
avatar
SigmaHQ
6 months ago
000
Detects linux package removal using builtin tools such as "yum", "apt", "apt-get" or "dpkg".
avatar
SigmaHQ Detections@sigmaHQ
avatar
SigmaHQ
6 months ago
000
Detects suspicious change of file privileges with chown and chmod commands
avatar
SigmaHQ Detections@sigmaHQ
avatar
SigmaHQ
6 months ago
000
Detects a potentially suspicious execution of a process located in the '/tmp/' folder
avatar
SigmaHQ Detections@sigmaHQ
avatar
SigmaHQ
6 months ago
000
Detects suspicious interactive bash as a parent to rather uncommon child processes
avatar
SigmaHQ Detections@sigmaHQ
avatar
SigmaHQ
6 months ago
000
Detects suspicious process command line that starts with a shell that executes something and finally gets piped into another shell
avatar
SigmaHQ Detections@sigmaHQ
avatar
SigmaHQ
6 months ago
000
Detects usage of the "touch" process in service file.
avatar
SigmaHQ Detections@sigmaHQ
avatar
SigmaHQ
6 months ago
000
Detects execution of a the file "execve_hijack" which is used by the Triple Cross rootkit as a way to elevate privileges
avatar
SigmaHQ Detections@sigmaHQ
avatar
SigmaHQ
6 months ago
000
Detects default install commands of the Triple Cross eBPF rootkit based on the "deployer.sh" script
avatar
SigmaHQ Detections@sigmaHQ
avatar
SigmaHQ
6 months ago
000
Detects changes of sensitive and critical files. Monitors files that you don't expect to change without planning on Linux system.
These files include, but are not limited to, system configuration files, authentication files, and critical application files.
Attackers often target these files to maintain persistence, escalate privileges, or disrupt system operations.
avatar
SigmaHQ Detections@sigmaHQ
avatar
SigmaHQ
6 months ago
000
Detects the creation of cron files in Cron directories, which could indicate potential persistence mechanisms being established by an attacker.
Note that not all cron file creations are malicious - legitimate system administration activities and software installations may also create cron files.
This detection should be investigated in context, considering factors such as the user creating the file, the timing of creation, and the contents of the cron job.
Focus investigation on unexpected cron files created by non-administrative users or during suspicious timeframes.
Additionally, it is recommended to review the contents of the newly created cron files to assess their intent.
Furthermore, it is suggested to baseline normal cron file creation and apply additional filters to reduce false positives based on the specific environment.
avatar
SigmaHQ Detections@sigmaHQ
avatar
SigmaHQ
6 months ago
000
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
avatar
Detections.ai Community
8 months ago
130116
Detects a script interpreter process (like node.js or bun) spawning a known credential scanning tool (e.g., trufflehog, gitleaks).
This behavior is indicative of an attempt to find and steal secrets, as seen in the "Shai-Hulud: The Second Coming" campaign.
avatar
SigmaHQ Detections@sigmaHQ
avatar
SigmaHQ
7 months ago
102
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
avatar
Detections.ai Community
8 months ago
6096
Page 41 of 51