Detection rules › Sigma

ADCS - Certighost Ghost Machine Account Creation

Status
experimental
Severity
high
Log source
product windows, service security
Author
Swachchhanda Shrawan Poudel (Nextron Systems)
Source
github.com/SigmaHQ/sigma

Detects the creation of a machine account whose name starts with 'GHOST', which is the naming convention used by the CVE-2026-54121 (Certighost) exploit tooling. The public proof-of-concept for Certighost creates a temporary machine account with a name of the form GHOST<random>$ before enrolling for a DC certificate via the cdc chase path. The attacker-controlled machine account is used as the requester identity in the certificate request; the cdc attribute then redirects the CA to a rogue host that returns a forged Domain Controller identity. The resulting certificate carries the DC's SID and DNS name, enabling full PKINIT authentication as the targeted DC followed by DCSync. A machine account creation event (4741) where TargetUserName starts with 'GHOST' and ends with '$' is a high-fidelity indicator of this attack tool's execution. Legitimate environments very rarely provision machine accounts with this prefix.

Known false positives

  • Unlikely

MITRE ATT&CK coverage

Telemetry coverage

Rule body

title: ADCS - Certighost Ghost Machine Account Creation
id: fa0bac5f-d170-4a91-9780-1ad71dc1f49e
status: experimental
description: |
    Detects the creation of a machine account whose name starts with 'GHOST', which is the
    naming convention used by the CVE-2026-54121 (Certighost) exploit tooling.

    The public proof-of-concept for Certighost creates a temporary machine account with a
    name of the form GHOST<random>$ before enrolling for a DC certificate via the cdc chase
    path. The attacker-controlled machine account is used as the requester identity in the
    certificate request; the cdc attribute then redirects the CA to a rogue host that returns
    a forged Domain Controller identity. The resulting certificate carries the DC's SID and
    DNS name, enabling full PKINIT authentication as the targeted DC followed by DCSync.

    A machine account creation event (4741) where TargetUserName starts with 'GHOST' and
    ends with '$' is a high-fidelity indicator of this attack tool's execution. Legitimate
    environments very rarely provision machine accounts with this prefix.
references:
    - https://github.com/aniqfakhrul/CVE-2026-54121
    - https://gist.github.com/H0j3n/a5ef2609b5f2944ac2390a191a534c26
author: Swachchhanda Shrawan Poudel (Nextron Systems)
date: 2026-07-30
tags:
    - attack.privilege-escalation
    - attack.credential-access
    - attack.persistence
    - attack.t1136.002
    - attack.t1649
    - cve.2026-54121
    - detection.emerging-threats
logsource:
    product: windows
    service: security
    definition: |
        Requirements:
            Audit Policy : Account Management > Audit Computer Account Management
detection:
    selection:
        EventID: 4741
        TargetUserName|startswith: 'GHOST'
        TargetUserName|endswith: '$'
    condition: selection
falsepositives:
    - Unlikely
level: high

Stages and Predicates

Stage 0: condition

selection

Stage 1: selection

selection:
    EventID: 4741
    TargetUserName|startswith: 'GHOST'
    TargetUserName|endswith: '$'

Indicators

These rows show field, operator, and value matches.

FieldKindValuesSearch
TargetUserNameends_with
  • $ corpus 11 (sigma 7, splunk 2, kusto 2)
field:"TargetUserName" kind:ends_with value:"$"
TargetUserNamestarts_with
  • GHOST
field:"TargetUserName" kind:starts_with value:"GHOST"