Potential Shadow Credentials added to AD Objectedit
Identify the modification of the msDS-KeyCredentialLink attribute in an Active Directory Computer or User Object. Attackers can abuse control over the object and create a key pair, append to raw public key in the attribute, and obtain persistent and stealthy access to the target user or computer object.
Rule type: query
Rule indices:
- winlogbeat-*
- logs-system.*
Severity: high
Risk score: 73
Runs every: 5 minutes
Searches indices from: now-9m (Date Math format, see also Additional look-back time)
Maximum alerts per execution: 100
References:
Tags:
- Elastic
- Host
- Windows
- Threat Detection
- Credential Access
- Active Directory
Version: 4 (version history)
Added (Elastic Stack release): 8.1.0
Last modified (Elastic Stack release): 8.4.0
Rule authors: Elastic
Rule license: Elastic License v2
Potential false positivesedit
Modifications in the msDS-KeyCredentialLink attribute can be done legitimately by the Azure AD Connect synchronization account or the ADFS service account. These accounts can be added as Exceptions.
Investigation guideedit
Rule queryedit
event.action:"Directory Service Changes" and event.code:"5136" and winlog.event_data.AttributeLDAPDisplayName:"msDS-KeyCredentialLink"
Threat mappingedit
Framework: MITRE ATT&CKTM
-
Tactic:
- Name: Credential Access
- ID: TA0006
- Reference URL: https://attack.mitre.org/tactics/TA0006/
-
Technique:
- Name: Modify Authentication Process
- ID: T1556
- Reference URL: https://attack.mitre.org/techniques/T1556/
Rule version historyedit
- Version 4 (8.4.0 release)
-
- Formatting only
- Version 2 (8.2.0 release)
-
- Formatting only