AD-DACL-15 - Unresolved SID count should be investigated

Contributed by Michael SouleAll contributors →

Overview

Unresolved SIDs in DACLs often indicate deleted users or groups, stale migration artifacts, or incomplete cleanup.

• Stale delegation detection: Old ACEs can remain after identities are removed
• Operational hygiene: Orphaned SID references make permissions harder to review and audit
• Migration validation: Unresolved SIDs can reveal accounts that were not fully remapped or retired

Control Type

Operational

Security Recommendation

• Investigate unresolved SID ACEs and determine whether they can be removed
• Validate that deprovisioning and migration processes clean up obsolete permissions
• Review privileged containers first, where stale ACEs can cause confusion during incident response

How the Test Works

This test reads $adState.DaclEntries and looks for entries whose IdentityReference starts with S-1-5-21, which commonly indicates a SID that did not resolve to a friendly name.

Related Tests

• Test-MtAdDaclUnresolvedSidDetails - Lists unresolved SID references by object
• Test-MtAdDaclDistinctIdentityCount - Counts distinct identities present in ACEs
• Test-MtAdDaclIdentityAceDistribution - Shows ACE distribution across identities

Test Metadata

Field	Value
Test ID	AD-DACL-15
Severity	Info
Suite	Active Directory
Category	Active Directory - DACL
PowerShell test	Test-MtAdDaclUnresolvedSidCount
Services	ActiveDirectory
Tags	AD, AD-DACL-15, AD.DACL

Source

• Test: tests/ad/dacl/Test.AD-DACL-15.ps1
• Documentation: tests/ad/dacl/Test.AD-DACL-15.md