Shell Invocation Via Ssh - Linux

Title: Shell Invocation Via Ssh - Linux
Status: test
Description: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.
References:
  -https://gtfobins.github.io/gtfobins/ssh/
  -https://www.elastic.co/guide/en/security/current/linux-restricted-shell-breakout-via-linux-binary-s.html
Author: Li Ling, Andy Parkidomo, Robert Rakowski, Blake Hartstein (Bloomberg L.P.)
Date: 2024-08-29
modified:None
Tags:

• -'attack.execution'
• -'attack.t1059'

Logsource:

• category: process_creation
• product: linux

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_*
Falsepositives:
  -Unknown
Level: high