M365AUDIT-001: Unified Audit Log enabled
- Platform
- Entra ID / M365
- Category
- Unified Audit & Logging
- Severity
- Critical
- Zero Trust pillar
- Visibility & Analytics (weight 2)
- Golden fixtures
- 3
- Branch coverage
- Observed: fixtures prove the verdicts they exercise
- Provenance
- baseline
What it checks
The Microsoft 365 Unified Audit Log records user and administrator activities across Exchange Online, SharePoint Online, OneDrive, Azure AD, Microsoft Teams, and other services, providing the foundational data source for security investigations. If unified auditing is disabled, the organization loses visibility into critical activities such as mailbox access, file sharing, permission changes, and administrative operations. Disabling the audit log is a known adversary technique used to cover tracks after compromising a tenant.
Recommended value
Unified Audit Log enabled organization-wide with no per-user or per-mailbox overrides disabling auditing
Remediation
Verify that unified audit logging is enabled by running Get-AdminAuditLogConfig and confirming that UnifiedAuditLogIngestionEnabled is set to True. If auditing is disabled, enable it immediately and investigate the audit history to determine when and by whom it was disabled, as this may indicate a security compromise. Set up a monitoring alert to detect any future attempts to disable the unified audit log and restrict the permissions required to modify audit log settings to a minimal set of trusted administrators.
Fixture-proven verdicts
Every verdict below is proven by a golden fixture in the module's gating test suite. This table derives from the last green run; it cannot be edited by hand.
| Scenario | Expected verdict |
|---|---|
| clean | PASS |
| known-bad | FAIL |
| throttled | Not Assessed |
Framework mappings
- CISA SCuBA
- MS.DEFENDER.6.1v1
- NIST SP 800-53
- AU-2, AU-3
- CIS M365 Benchmark
- 3.1.1
- MITRE ATT&CK
- T1562.008