Bitbucket audit: User login failed authentication events

Flags Bitbucket audit events for user login failures in the authentication category.

FreeReviewedSigma · Medium · v5
Product
bitbucket
Service
audit
Author
Muhammad Faisal (@faisalusuf) (SigmaHQ), DRL 1.1
Published
2024-02-25
Updated
2026-07-31

ATT&CK techniques

Initial Access → Cred Access
  1. Recon

  2. Resource Dev

  3. Execution

  4. Cred Access

  5. Discovery

  6. Lateral Movement

  7. Collection

  8. C2

  9. Exfiltration

  10. Impact

What it detects

This rule flags Bitbucket audit events where authentication fails due to a user login failure. Failed logins can indicate credential guessing, stolen credentials, or attempts to access accounts without authorization. It relies on Bitbucket audit telemetry containing the authentication category and the specific action indicating a failed login attempt.

Related detections9 linkedT1110 — drag to rearrange
Azure Sign-in Success with Legacy Client User-Agent Indicators (MFA Bypass Suspicion)
Azure AD Sign-ins Using Legacy Authentication Client Applications
Azure Sign-in Logs: Conditional Access Blocked Sign-in Failures (ResultType 53003)
Azure Sign-in Logs: MFA Denied Based on Authentication Requirement
Azure Sign-in Log MFA Interrupted via Strong Auth Failures
Azure Sign-in Logs: Conditional Access Blocks User Token Issuance (ResultType 53003)
Suspicious Google Cloud Function Create or Update Triggering Build
Malicious SQL Server - Brutforce Enumeration with Non Existing Users - Login (via application)
Malicious Brutforce Enumeration with Non Existing Users - Login (via security)
Bitbucket audit: User login failed authentication events
Pivot detection · T1110 · 9 related

Changelog

v5
  1. v5
    Candidate ingested via manual entry.2026-07-31
  2. v4
    Candidate ingested via manual entry.2026-07-31
  3. v3
    Candidate ingested via manual entry.2026-07-31
  4. v2
    Candidate ingested via manual entry.2026-07-31
  5. v1
    No changelog recorded for this version.2026-07-30

Detection content is published as a reviewed draft. Tune thresholds and exclusions against your own telemetry before enabling this rule for alerting.