Bitbucket User Login Failure Via SSH — Sigma Rule

Rule metadata and linked tags

Author: Muhammad Faisal (@faisalusuf). Source status: test; severity: medium. Source dates: 2024-02-25 / not supplied.

{
  "product": "bitbucket",
  "service": "audit",
  "definition": "Requirements: \"Advance\" log level is required to receive these audit events."
}

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: 3ba6488a1c73a35580d58210685d5094da88da0f52a4d0c58c10856998ecc1ed

Detection logic

Original source YAML. Source-tag agreement is not proof of complete semantic coverage. This rule has not been compiled for a SIEM backend or validated against live telemetry here.

title: Bitbucket User Login Failure Via SSH
id: d3f90469-fb05-42ce-b67d-0fded91bbef3
status: test
description: |
    Detects SSH user login access failures.
    Please note that this rule can be noisy and is recommended to use with correlation based on "author.name" field.
references:
    - https://confluence.atlassian.com/bitbucketserver/view-and-configure-the-audit-log-776640417.html
    - https://confluence.atlassian.com/bitbucketserver/enable-ssh-access-to-git-repositories-776640358.html
author: Muhammad Faisal (@faisalusuf)
date: 2024-02-25
tags:
    - attack.lateral-movement
    - attack.credential-access
    - attack.t1021.004
    - attack.t1110
logsource:
    product: bitbucket
    service: audit
    definition: 'Requirements: "Advance" log level is required to receive these audit events.'
detection:
    selection:
        auditType.category: 'Authentication'
        auditType.action: 'User login failed(SSH)'
    condition: selection
falsepositives:
    - Legitimate user wrong password attempts.
level: medium

Original YAML and metadata in JSON

False positives

• Legitimate user wrong password attempts.

Source references

• https://confluence.atlassian.com/bitbucketserver/view-and-configure-the-audit-log-776640417.html
• https://confluence.atlassian.com/bitbucketserver/enable-ssh-access-to-git-repositories-776640358.html