Detectionhightest

Shell Invocation Via Ssh - Linux

Detects the use of the "ssh" utility to execute a shell. Such behavior may be associated with privilege escalation, unauthorized command execution, or to break out from restricted environments.

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Launch

Li Ling, Andy Parkidomo, Robert Rakowski, Blake Hartstein (Bloomberg L.P.)Created Thu Aug 298737b7f6-8df3-4bb7-b1da-06019b99b687linux

Log Source

LinuxProcess Creation

ProductLinux← raw: linux

CategoryProcess Creation← raw: process_creation

Events generated when a new process is spawned on the system. Covers command-line arguments, parent/child relationships, and process metadata.

Detection Logic

detection:
    selection_img:
        Image|endswith: '/ssh'
        CommandLine|contains:
            - 'ProxyCommand=;'
            - 'permitlocalcommand=yes'
            - 'localhost'
    selection_cli:
        CommandLine|contains:
            - '/bin/bash'
            - '/bin/dash'
            - '/bin/fish'
            - '/bin/sh'
            - '/bin/zsh'
            - 'sh 0<&2 1>&2'
            - 'sh 1>&2 0<&2'
    condition: all of selection_*