sigmahighHunting

Suspicious Invocation of Shell via AWK - Linux

Detects the execution of "awk" or it's sibling commands, to invoke a shell using the system() function. This behavior is commonly associated with attempts to execute arbitrary commands or escalate privileges, potentially leading to unauthorized access or further exploitation.

MITRE ATT&CK

T1059

execution

Detection Query

selection_img:
  Image|endswith:
    - /awk
    - /gawk
    - /mawk
    - /nawk
  CommandLine|contains: BEGIN {system
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.executionattack.t1059

Raw Content

title: Suspicious Invocation of Shell via AWK - Linux
id: 8c1a5675-cb85-452f-a298-b01b22a51856
status: test
description: |
    Detects the execution of "awk" or it's sibling commands, to invoke a shell using the system() function.
    This behavior is commonly associated with attempts to execute arbitrary commands or escalate privileges, potentially leading to unauthorized access or further exploitation.
references:
    - https://gtfobins.github.io/gtfobins/awk/#shell
    - https://gtfobins.github.io/gtfobins/gawk/#shell
    - https://gtfobins.github.io/gtfobins/nawk/#shell
    - https://gtfobins.github.io/gtfobins/mawk/#shell
author: Li Ling, Andy Parkidomo, Robert Rakowski, Blake Hartstein (Bloomberg L.P.)
date: 2024-09-02
tags:
    - attack.execution
    - attack.t1059
logsource:
    category: process_creation
    product: linux
detection:
    selection_img:
        Image|endswith:
            - '/awk'
            - '/gawk'
            - '/mawk'
            - '/nawk'
        CommandLine|contains: 'BEGIN {system'
    selection_cli:
        CommandLine|contains:
            - '/bin/bash'
            - '/bin/dash'
            - '/bin/fish'
            - '/bin/sh'
            - '/bin/zsh'
    condition: all of selection_*
falsepositives:
    - Unknown
level: high