Sigma rule: Cisco ASA Exploitation Activity - Proxy

A detection rule from the SigmaHQ repository, shown as its author published it. Dataset version ref-7e51e3c665d7, updated 2025-11-20T00:00:00.000Z.

Rule

Title
Cisco ASA Exploitation Activity - Proxy
Status
experimental
Level
high
Author
Swachchhanda Shrawan Poudel (Nextron Systems)
Date
2025-11-20
File
rules-emerging-threats/2025/Exploits/CVE-2025-20333/proxy_exploit_cve_2025_20333.yml
Commit
ccbb0369507f796db0b0ae6854c8a2be471b9d84

Detects suspicious requests to Cisco ASA WebVpn via proxy logs associated with CVE-2025-20333 and CVE-2025-20362 exploitation.

Log source

category
proxy

Detection

selection:
    cs-method: 'GET'
    cs-uri-stem:
        - '/+CSCOU+/MacTunnelStart.jar'
        - '/+CSCOL+/csvrloader64.cab'
        - '/+CSCOL+/csvrloader.jar'
condition: selection

False positives (as the rule lists them)

  • Unknown

Tags

  • attack.initial-access
  • attack.t1190
  • cve.2025-20333
  • cve.2025-20362
  • detection.emerging-threats

CVEs this rule names

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/Exploits/CVE-2025-20333/proxy_exploit_cve_2025_20333.yml

Sources and licences

  • SigmaHQ

    "Cisco ASA Exploitation Activity - Proxy" by Swachchhanda Shrawan Poudel (Nextron Systems) (SigmaHQ). Rule: https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules-emerging-threats/2025/Exploits/CVE-2025-20333/proxy_exploit_cve_2025_20333.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: Cisco ASA Exploitation Activity - Proxy",
entity page, dataset version ref-7e51e3c665d7, updated 2025-11-20T00:00:00.000Z,
https://ransomware-tracker.com/detections/sigma/15697955-6a29-47ca-92e9-0e05efae3260 (accessed 2026-11-03).
Underlying source: SigmaHQ rule 15697955-6a29-47ca-92e9-0e05efae3260, 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.