DC Machine Account TGT Request from Non-DC Source IP
experimentalhighdescription
What this is, in brief.
Detects a Kerberos TGT request (Event 4768) for a known Domain Controller machine account originating from an IP address that is not a known Domain Controller. DC machine accounts should only request TGTs from their own IP. Any TGT request for a DC account from a workstation or non-DC host is anomalous and indicates one of the following: - PKINIT abuse (CVE-2026-54121 / Certighost): attacker authenticating as a DC via a forged certificate from their workstation - Overpass-the-Hash: attacker converting a stolen DC machine account NTLM hash into a Kerberos TGT - Pass-the-Hash (RC4): attacker using the DC machine account hash directly with Kerberos
tags
rule source (YAML)
title: DC Machine Account TGT Request from Non-DC Source IP
id: 9c5d2b84-1f7e-4a3c-d6b8-e04f9a17c523
status: experimental
description: |
Detects a Kerberos TGT request (Event 4768) for a known Domain Controller machine account
originating from an IP address that is not a known Domain Controller. DC machine accounts
should only request TGTs from their own IP. Any TGT request for a DC account from a
workstation or non-DC host is anomalous and indicates one of the following:
- PKINIT abuse (CVE-2026-54121 / Certighost): attacker authenticating as a DC via a
forged certificate from their workstation
- Overpass-the-Hash: attacker converting a stolen DC machine account NTLM hash into a
Kerberos TGT
- Pass-the-Hash (RC4): attacker using the DC machine account hash directly with Kerberos
references:
- https://github.com/aniqfakhrul/CVE-2026-54121
- https://gist.github.com/H0j3n/a5ef2609b5f2944ac2390a191a534c26
author: Swachchhanda Shrawan Poudel (Nextron Systems)
date: 2026-07-29
tags:
- attack.credential-access
- attack.lateral-movement
- attack.t1649
- attack.t1550.003
- attack.t1558.001
- cve.2026-54121
logsource:
product: windows
service: security
detection:
selection:
EventID: 4768
Status: '0x0'
TargetUserName|endswith: '$'
TargetUserName|expand: '%dc_machine_accounts%'
filter_main_dc_source:
IpAddress|expand: '%dc_ip_addresses%'
filter_main_loopback:
- IpAddress:
- '127.0.0.1'
- '::1'
- '::ffff:127.0.0.1'
- '-'
- IpAddress|startswith: 'fe80:'
condition: selection and not 1 of filter_main_*
falsepositives:
- Unlikely if %dc_machine_accounts% and %dc_ip_addresses% are correctly populated.
level: high
detects techniques (3)
ATT&CK techniques this enables or maps to.
references
External citations — patches, advisories, analysis.