Suspicious Linux Base64 Encoded Pipe to Shell (via process_creation)

title: Suspicious Linux Base64 Encoded Pipe to Shell (via process_creation)
id: b33cf7dd-92a8-561d-b12f-00cfac8edf33
status: stable
description: This rule detects anomalous process command line that uses base64 encoded input for execution with a shell
references:
    - https://attack.mitre.org/techniques/T1140/
    - https://github.com/arget13/DDexec
    - https://www.mandiant.com/resources/blog/barracuda-esg-exploited-globally
author: Huntrule Team
date: 2026-04-04
tags:
    - attack.stealth
    - attack.t1140
logsource:
    product: linux
    category: process_creation
detection:
    selection_base64:
        CommandLine|contains: 'base64 '
    selection_exec:
        - CommandLine|contains:
              - '| bash '
              - '| sh '
              - '|bash '
              - '|sh '
        - CommandLine|endswith:
              - ' |sh'
              - '| bash'
              - '| sh'
              - '|bash'
    condition: all of selection_*
falsepositives:
    - Unknown
level: medium