Posture check · Delegation and Kerberos
Service account allows the weak RC4 cipher for Kerberos (T1558.003)
This service account allows RC4 for Kerberos tickets. Tickets encrypted with RC4 can be cracked offline. This check assumes your domain controllers have the July 2026 or later update and can't see a registry override on them.
Why it matters
Any authenticated user can request a ticket for this account and try to crack its password.
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 attributes
msDS-SupportedEncryptionTypes,servicePrincipalName,userAccountControl,accountEnabled,objectSidandobjectClass
Tiered Fidelity™ level: Constrained
Every finding from this check carries the Constrained level.
- TheoreticalConfigured in the directory. Nothing else checked.
- ConstrainedThis checkA constraint on it has been checked.
- ValidatedTelemetry has seen it in use.
Why there's no automatic fix
GraphnAI doesn't change an account's allowed encryption, because a service that only supports RC4 stops working.
How to fix it
Set this account to AES only and give it a long random password.
Related checks
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.