Sigma rule: Shellshock Expression

A detection rule from the SigmaHQ repository, shown as its author published it. Dataset version ref-afbc42adc6d1, updated 2022-10-09T00:00:00.000Z.

Rule

Title
Shellshock Expression
Status
test
Level
high
Author
Florian Roth (Nextron Systems)
Date
2017-03-14
Modified
2022-10-09
File
rules/linux/builtin/lnx_shellshock.yml
Commit
ccbb0369507f796db0b0ae6854c8a2be471b9d84

Detects shellshock expressions in log files

Log source

product
linux

Detection

keywords:
    - '(){:;};'
    - '() {:;};'
    - '() { :;};'
    - '() { :; };'
condition: keywords

False positives (as the rule lists them)

  • Unknown

Tags

  • attack.persistence
  • attack.t1505.003

MITRE ATT&CK ids this rule names

References

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/builtin/lnx_shellshock.yml

Sources and licences

  • SigmaHQ

    "Shellshock Expression" by Florian Roth (Nextron Systems) (SigmaHQ). Rule: https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules/linux/builtin/lnx_shellshock.yml.
    Licensed under the Detection Rule License (DRL) 1.1: https://github.com/SigmaHQ/Detection-Rule-License

    Detection Rule License (DRL) 1.1

Cite this page

Dragons Eye Ransomware Tracker, "Sigma rule: Shellshock Expression",
entity page, dataset version ref-afbc42adc6d1, updated 2022-10-09T00:00:00.000Z,
https://ransomware-tracker.com/detections/sigma/c67e0c98-4d39-46ee-8f6b-437ebf6b950e (accessed 2026-11-03).
Underlying source: SigmaHQ rule c67e0c98-4d39-46ee-8f6b-437ebf6b950e, commit ccbb0369507f796db0b0ae6854c8a2be471b9d84.

Pages change. The dataset version identifies the data, but no archive of old versions is kept, so this citation cannot be replayed later.