Suspicious Linux Shell Pipe to Shell (via process_creation)

title: Suspicious Linux Shell Pipe to Shell (via process_creation)
id: 2050f520-5ce3-58ed-a626-a6fa667d3afc
status: stable
description: This rule detects anomalous process command line that starts with a shell that runs something and finally gets piped into another shell
references:
    - https://attack.mitre.org/techniques/T1140/
    - Internal Research
author: Huntrule Team
date: 2026-01-13
tags:
    - attack.stealth
    - attack.t1140
logsource:
    product: linux
    category: process_creation
detection:
    selection:
        CommandLine|startswith:
            - 'sh -c '
            - 'bash -c '
    selection_exec:
        - CommandLine|contains:
              - '| bash '
              - '| sh '
              - '|bash '
              - '|sh '
        - CommandLine|endswith:
              - '| bash'
              - '| sh'
              - '|bash'
              - ' |sh'
    condition: all of selection*
falsepositives:
    - Unknown
level: medium