Sigma rule: Suspicious Invocation of Shell via AWK - Linux

Rule

Title

Suspicious Invocation of Shell via AWK - Linux

Status

test

Level

high

Author

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

Date

2024-09-02

File

rules/linux/process_creation/proc_creation_lnx_awk_shell_spawn.yml

Commit

ccbb0369507f796db0b0ae6854c8a2be471b9d84

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.

Log source

product

linux

category

process_creation

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_*

False positives (as the rule lists them)

• Unknown

Tags

• attack.execution
• attack.t1059

MITRE ATT&CK ids this rule names

• T1059

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

Read on 2026-11-03T00:58:21.399Z under licence sigma-drl-1.1@d5f4c36a from https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules/linux/process_creation/proc_creation_lnx_awk_shell_spawn.yml