Modification of the msPKIAccountCredentials

edit

Modification of the msPKIAccountCredentials

edit

Identify the modification of the msPKIAccountCredentials attribute in an Active Directory User Object. Attackers can abuse the credentials roaming feature to overwrite an arbitrary file for privilege escalation. ms-PKI-AccountCredentials contains binary large objects (BLOBs) of encrypted credential objects from the credential manager store, private keys, certificates, and certificate requests.

Rule type: query

Rule indices:

  • winlogbeat-*
  • logs-system.*
  • logs-windows.*

Severity: medium

Risk score: 47

Runs every: 5m

Searches indices from: now-9m (Date Math format, see also Additional look-back time)

Maximum alerts per execution: 100

References:

Tags:

  • Domain: Endpoint
  • OS: Windows
  • Use Case: Threat Detection
  • Data Source: Active Directory
  • Tactic: Privilege Escalation
  • Use Case: Active Directory Monitoring

Version: 9

Rule authors:

  • Elastic

Rule license: Elastic License v2

Setup

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)

Rule query

edit
event.action:"Directory Service Changes" and event.code:"5136" and
  winlog.event_data.AttributeLDAPDisplayName:"msPKIAccountCredentials" and winlog.event_data.OperationType:"%%14674" and
  not winlog.event_data.SubjectUserSid : "S-1-5-18"

Framework: MITRE ATT&CKTM