Sigma rule: Decode Base64 Encoded Text

A detection rule from the SigmaHQ repository, shown as its author published it. Dataset version ref-046e5cd642fc, updated 2021-11-27T00:00:00.000Z.

Rule

Title
Decode Base64 Encoded Text
Status
test
Level
low
Author
Daniil Yugoslavskiy, oscd.community
Date
2020-10-19
Modified
2021-11-27
File
rules/linux/process_creation/proc_creation_lnx_base64_decode.yml
Commit
ccbb0369507f796db0b0ae6854c8a2be471b9d84

Detects usage of base64 utility to decode arbitrary base64-encoded text

Log source

product
linux
category
process_creation

Detection

selection:
    Image|endswith: '/base64'
    CommandLine|contains: '-d' # Also covers "--decode"
condition: selection

False positives (as the rule lists them)

  • Legitimate activities

Tags

  • attack.stealth
  • attack.t1027

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/process_creation/proc_creation_lnx_base64_decode.yml

Sources and licences

  • SigmaHQ

    "Decode Base64 Encoded Text" by Daniil Yugoslavskiy, oscd.community (SigmaHQ). Rule: https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules/linux/process_creation/proc_creation_lnx_base64_decode.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: Decode Base64 Encoded Text",
entity page, dataset version ref-046e5cd642fc, updated 2021-11-27T00:00:00.000Z,
https://ransomware-tracker.com/detections/sigma/e2072cab-8c9a-459b-b63c-40ae79e27031 (accessed 2026-11-03).
Underlying source: SigmaHQ rule e2072cab-8c9a-459b-b63c-40ae79e27031, 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.