sigmahighHunting

Shell Execution via Flock - Linux

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

MITRE ATT&CK

T1083

discovery

Detection Query

selection_img:
  Image|endswith: /flock
  CommandLine|contains: " -u "
selection_cli:
  CommandLine|contains:
    - /bin/bash
    - /bin/dash
    - /bin/fish
    - /bin/sh
    - /bin/zsh
condition: all of selection_*

Author

Li Ling, Andy Parkidomo, Robert Rakowski, Blake Hartstein (Bloomberg L.P.)

Created

2024-09-02

Data Sources

linuxProcess Creation Events

Platforms

linux

References

Tags

attack.discoveryattack.t1083

Raw Content

title: Shell Execution via Flock - Linux
id: 4b09c71e-4269-4111-9cdd-107d8867f0cc
status: test
description: |
    Detects the use of the "flock" command 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/flock/#shell
    - 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: 2024-09-02
tags:
    - attack.discovery
    - attack.t1083
logsource:
    category: process_creation
    product: linux
detection:
    selection_img:
        Image|endswith: '/flock'
        CommandLine|contains: ' -u '
    selection_cli:
        CommandLine|contains:
            - '/bin/bash'
            - '/bin/dash'
            - '/bin/fish'
            - '/bin/sh'
            - '/bin/zsh'
    condition: all of selection_*
falsepositives:
    - Unknown
level: high