Suspicious Modification of msDS-KeyCredentialLink for Shadow Credential Abuse
- Product
- windows
- Service
- security
- Author
- HuntRule
- Published
- 2026-10-01
- Updated
- 2026-10-01
ATT&CK techniques
Persistence → Lateral MovementRecon
Resource Dev
Initial Access
Execution
Persistence
Priv Esc
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact
What it detects
This rule detects Active Directory directory-service changes writing to the msDS-KeyCredentialLink attribute, the shadow-credential primitive used in the Huntress dMSA Ouroboros technique to obtain PKINIT authentication material on Windows Server 2025. Populating this attribute lets an attacker request Kerberos tickets and extract credentials for the target object. Modification outside device registration or trusted CA workflows is a strong indicator of credential-access abuse.
Reporting behind it
- huntress.comhttps://www.huntress.com/blog/dmsa-ouroboros-credential-extraction-windows-server-2025
- attack.mitre.orghttps://attack.mitre.org/techniques/T1558/
- unit42.paloaltonetworks.comhttps://unit42.paloaltonetworks.com/active-directory-certificate-services-exploitation/
- attack.mitre.orghttps://attack.mitre.org/techniques/T1556/004/
- attack.mitre.orghttps://attack.mitre.org/techniques/T1550/003/
Detection content is published as a reviewed draft. Tune thresholds and exclusions against your own telemetry before enabling this rule for alerting.
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