Sigma rule: Commvault QLogin with PublicSharingUser and GUID Password (CVE-2025-57788)

A detection rule from the SigmaHQ repository, shown as its author published it. Dataset version ref-fbe01d91fdec, updated 2025-10-20T00:00:00.000Z.

Rule

Title
Commvault QLogin with PublicSharingUser and GUID Password (CVE-2025-57788)
Status
experimental
Level
medium
Author
Swachchhanda Shrawan Poudel (Nextron Systems)
Date
2025-10-20
File
rules-emerging-threats/2025/Exploits/CVE-2025-57788/proc_creation_win_exploit_cve_2025_57788.yml
Commit
ccbb0369507f796db0b0ae6854c8a2be471b9d84

Detects a qlogin.exe command attempting to authenticate as the internal `_+_PublicSharingUser_` using a GUID as the password.
This could be an indicator of an attacker exploiting CVE-2025-57788 to gain initial access using leaked credentials.

Log source

product
windows
category
process_creation

Detection

selection:
    CommandLine|contains|all:
        - 'qlogin'
        - '_+_PublicSharingUser_'
    # Detects the use of a GUID as the password, which is indicative of an exploit attempt
    CommandLine|re: '[A-F0-9]{8}-[A-F0-9]{4}-[A-F0-9]{4}-[A-F0-9]{4}-[A-F0-9]{12}'
condition: selection

False positives (as the rule lists them)

  • Legitimate administrative scripts that use the `_+_PublicSharingUser_` account for valid purposes.

Tags

  • attack.privilege-escalation
  • attack.persistence
  • attack.initial-access
  • attack.stealth
  • attack.t1078.001
  • detection.emerging-threats
  • cve.2025-57788

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-2025-57788/proc_creation_win_exploit_cve_2025_57788.yml

Sources and licences

  • SigmaHQ

    "Commvault QLogin with PublicSharingUser and GUID Password (CVE-2025-57788)" by Swachchhanda Shrawan Poudel (Nextron Systems) (SigmaHQ). Rule: https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules-emerging-threats/2025/Exploits/CVE-2025-57788/proc_creation_win_exploit_cve_2025_57788.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: Commvault QLogin with PublicSharingUser and GUID Password (CVE-2025-57788)",
entity page, dataset version ref-fbe01d91fdec, updated 2025-10-20T00:00:00.000Z,
https://ransomware-tracker.com/detections/sigma/917789e1-2c1f-4bf5-8c91-6f71a017f469 (accessed 2026-11-03).
Underlying source: SigmaHQ rule 917789e1-2c1f-4bf5-8c91-6f71a017f469, 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.