KRBTGT Delegation Backdoor

Identifies the modification of the msDS-AllowedToDelegateTo attribute to KRBTGT. Attackers can use this technique to maintain persistence to the domain by having the ability to request tickets for the KRBTGT service.

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
Persistence
Active Directory

Version: 5

Rule authors:

Elastic

Rule license: Elastic License v2

Investigation guide

edit

## Setup

The 'Audit User Account Management' 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 >
Account Management >
Audit User Account Management (Success,Failure)
```

Rule query

edit

event.action:modified-user-account and event.code:4738 and winlog.event_data.AllowedToDelegateTo:*krbtgt*

Framework: MITRE ATT&CK^TM

Tactic:
- Name: Persistence
- ID: TA0003
- Reference URL: https://attack.mitre.org/tactics/TA0003/
Technique:
- Name: Account Manipulation
- ID: T1098
- Reference URL: https://attack.mitre.org/techniques/T1098/
Tactic:
- Name: Credential Access
- ID: TA0006
- Reference URL: https://attack.mitre.org/tactics/TA0006/
Technique:
- Name: Steal or Forge Kerberos Tickets
- ID: T1558
- Reference URL: https://attack.mitre.org/techniques/T1558/

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