Sigma rule: FunkLocker Ransomware File Creation

A detection rule from the SigmaHQ repository, shown as its author published it. Dataset version ref-b937b53c984a, updated 2025-08-08T00:00:00.000Z.

Rule

Title
FunkLocker Ransomware File Creation
Status
experimental
Level
high
Author
Saiprashanth Pulisetti ( @Prashanthblogs)
Date
2025-08-08
File
rules-emerging-threats/2025/Malware/file_event_win_malware_funklocker_ransomware_extension.yml
Commit
ccbb0369507f796db0b0ae6854c8a2be471b9d84

Detects the creation of files with the ".funksec" extension, which is appended to encrypted files by the FunkLocker ransomware.

Log source

product
windows
category
file_event

Detection

selection:
    TargetFilename|endswith: '.funksec'
condition: selection

False positives (as the rule lists them)

  • Unlikely

Tags

  • attack.impact
  • attack.t1486
  • detection.emerging-threats

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-emerging-threats/2025/Malware/file_event_win_malware_funklocker_ransomware_extension.yml

Sources and licences

  • SigmaHQ

    "FunkLocker Ransomware File Creation" by Saiprashanth Pulisetti ( @Prashanthblogs) (SigmaHQ). Rule: https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules-emerging-threats/2025/Malware/file_event_win_malware_funklocker_ransomware_extension.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: FunkLocker Ransomware File Creation",
entity page, dataset version ref-b937b53c984a, updated 2025-08-08T00:00:00.000Z,
https://ransomware-tracker.com/detections/sigma/2c76a22b-702d-48fd-8fa9-e41e2fe203b3 (accessed 2026-11-03).
Underlying source: SigmaHQ rule 2c76a22b-702d-48fd-8fa9-e41e2fe203b3, 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.