Operation Poisson: OpenSSH Server Install for Persistent Backdoor Access
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.
Splunk (SPL)
