Sigma rule: Potential Exfiltration of Compressed Files

A detection rule from the SigmaHQ repository, shown as its author published it. Dataset version ref-ae1ee5ae0fad, updated 2023-03-24T00:00:00.000Z.

Rule

Title
Potential Exfiltration of Compressed Files
Status
unsupported
Level
medium
Author
Greg Howell, OTR (Open Threat Research)
Date
2020/04/05
Modified
2023/03/24
File
unsupported/zeek/zeek_http_exfiltration_compressed_files.yml
Commit
ccbb0369507f796db0b0ae6854c8a2be471b9d84

This rule detects potential exfiltration by looking for a few compression extensions in the uri and signs of compression in the mime type, file type, and http body

Log source

product
zeek
service
http

Detection

selection1:
    uri|endswith:
     - '.7z'
     - '.zip'
     - '.rar'
    mime_types|endswith: 'compressed'
selection3:
    filetype|endswith: 'compressed'
selection4:
    http.bodyMagic|endswith: 'compressed'
    http.method: PUT
condition: selection1 or selection3 or selection4

False positives (as the rule lists them)

  • Legitimate upload/download of archives

Tags

  • attack.exfiltration
  • attack.t1560.001
  • attack.t1005

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/unsupported/zeek/zeek_http_exfiltration_compressed_files.yml

Sources and licences

  • SigmaHQ

    "Potential Exfiltration of Compressed Files" by Greg Howell, OTR (Open Threat Research) (SigmaHQ). Rule: https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/unsupported/zeek/zeek_http_exfiltration_compressed_files.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: Potential Exfiltration of Compressed Files",
entity page, dataset version ref-ae1ee5ae0fad, updated 2023-03-24T00:00:00.000Z,
https://ransomware-tracker.com/detections/sigma/0d47e3f6-357f-4534-928c-202631d065fa (accessed 2026-11-03).
Underlying source: SigmaHQ rule 0d47e3f6-357f-4534-928c-202631d065fa, 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.