Posture check · Account security
Well-known privileged SID in sIDHistory (T1134.005)
The account's sIDHistory holds a RID under 1000 from any domain (such as Domain Admins, 512) or a built-in administrative group (such as Administrators).
Why it matters
sIDHistory is honored for access exactly like a real group membership. A privileged identifier planted there grants that privilege invisibly, and it is near-certain evidence of a prior compromise that injected it.
How GraphnAI finds it
It runs after every sync, on each connected domain or tenant on its own. It applies to Active Directory.
It reads:
- The directory attribute
sIDHistory
Tiered Fidelity™ level: Theoretical
Every finding from this check carries the Theoretical level.
- TheoreticalThis checkConfigured in the directory. Nothing else checked.
- ConstrainedA constraint on it has been checked.
- ValidatedTelemetry has seen it in use.
How Select Fire™ contains it
How to fix it
Remove the injected identifier from the account's sIDHistory and investigate how it was added. Treat the account, and the domain, as compromised until the entry is explained.
What Select Fire does
Select Fire opens from the finding and simulates each change on your live graph before anything changes in your directory. These steps contain a suspected compromise.
- Remove a SID history entrySemi-Auto: you authorize each change. Full-Auto never runs it.
Removing the identifier takes away every access the account had through it, which it may use legitimately today. GraphnAI can't put the entry back, so check what it grants first.
MITRE ATT&CK® technique names and MITRE D3FEND™ technique labels: © The MITRE Corporation. This work is reproduced and distributed with the permission of The MITRE Corporation. ATT&CK® is a registered trademark and D3FEND™ a trademark of The MITRE Corporation.
See it on your own directory.
The Public Preview is free for 30 days from your first sync, on your own server.