Detection rules › Elastic

Potential Active Directory Replication Account Backdoor

Author
Elastic
Source
upstream

Identifies the modification of the nTSecurityDescriptor attribute in a domain object with rights related to DCSync to a user/computer account. Attackers can use this backdoor to re-obtain access to hashes of any user/computer.

MITRE ATT&CK coverage

TacticTechniques
PersistenceT1098 Account Manipulation
Privilege EscalationT1098 Account Manipulation
Credential AccessT1003 OS Credential Dumping, T1003.006 OS Credential Dumping: DCSync

Event coverage

ProviderEvent IDTitle
Security-Auditing5136A directory service object was modified.

Stages and Predicates

Stage 1: kql:query

winlog.event_data.AttributeLDAPDisplayName:"nTSecurityDescriptor" and winlog.event_data.AttributeValue:"1131f6aa-9c07-11d1-f79f-00c04fc2dcd2;;S-1-5-21-" and winlog.event_data.AttributeValue:"1131f6ad-9c07-11d1-f79f-00c04fc2dcd2;;S-1-5-21-" and winlog.event_data.AttributeValue:"89e95b76-444d-4c62-991a-0facbeda640c;;S-1-5-21-"

Indicators

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.

FieldKindValues
winlog.event_data.AttributeLDAPDisplayNameeq
  • nTSecurityDescriptor
winlog.event_data.AttributeValuewildcard
  • *1131f6aa-9c07-11d1-f79f-00c04fc2dcd2;;S-1-5-21-*
  • *1131f6ad-9c07-11d1-f79f-00c04fc2dcd2;;S-1-5-21-*
  • *89e95b76-444d-4c62-991a-0facbeda640c;;S-1-5-21-*