IMPORTANT: No additional bug fixes or documentation updates
will be released for this version. For the latest information, see the
current release documentation.
Potential Shadow Credentials added to AD Object
editPotential Shadow Credentials added to AD Object
editIdentify 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: 5m
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: 5
Rule authors:
- Elastic
Rule license: Elastic License v2
Investigation guide
edit## Setup The 'Audit Directory Service Changes' logging policy must be configured for (Success, Failure). Steps to implement the logging policy with Advanced Audit Configuration: ``` Computer Configuration > Policies > Windows Settings > Security Settings > Advanced Audit Policies Configuration > Audit Policies > DS Access > Audit Directory Service Changes (Success,Failure) ``` The above policy does not cover User objects, so we need to set up an AuditRule using https://github.com/OTRF/Set-AuditRule. As this specifies the msDS-KeyCredentialLink Attribute GUID, it is expected to be low noise. ``` Set-AuditRule -AdObjectPath 'AD:\CN=Users,DC=Domain,DC=com' -WellKnownSidType WorldSid -Rights WriteProperty -InheritanceFlags Children -AttributeGUID 5b47d60f-6090-40b2-9f37-2a4de88f3063 -AuditFlags Success ```
Rule query
editevent.action:"Directory Service Changes" and event.code:"5136" and winlog.event_data.AttributeLDAPDisplayName:"msDS-KeyCredentialLink"
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/