Administrator login impersonation with forged Golden ticket

Status: stable
Severity: high
Log source: product windows, service security
Author: mdecrevoisier
Source: github.com/mdecrevoisier/SIGMA-detection-rules

Detects scenarios where an attacker used a forged Golden ticket to login on a remote host. Per default or if specified, the ticket will be forged using the builtin administrator account (SID *-500). However, and it frequent cases, a non suspicious user name will be specificied during the forge in order to evade security monitoring. The rule works based on this trick.

Known false positives

MITRE ATT&CK coverage

Tactic	Techniques
Credential Access	`T1558.001` Steal or Forge Kerberos Tickets: Golden Ticket

Telemetry coverage

Provider	Record / event type
Security-Auditing	Event ID 4624: An account was successfully logged on.

Rule body

title: Administrator login impersonation with forged Golden ticket
description: Detects scenarios where an attacker used a forged Golden ticket to login on a remote host. Per default or if specified, the ticket will be forged using the builtin administrator account (SID *-500). However, and it frequent cases, a non suspicious user name will be specificied during the forge in order to evade security monitoring. The rule works based on this trick.
references:
- https://github.com/mdecrevoisier/EVTX-to-MITRE-Attack/tree/master/TA0006-Credential%20Access/T1558-Steal%20or%20Forge%20Kerberos%20Tickets
- https://infosecwriteups.com/forest-an-asreproast-dcsync-and-golden-ticket-hackthebox-walkthrough-ade8dcdd1ee5
- https://attack.stealthbits.com/how-golden-ticket-attack-works
- https://www.hackingarticles.in/domain-persistence-golden-ticket-attack/
- https://adsecurity.org/?p=1515
- https://en.it-pirate.eu/azure-atp-golden-ticket-attack-how-golden-ticket-attacks-work/
- https://www.ired.team/offensive-security-experiments/active-directory-kerberos-abuse/kerberos-golden-tickets
- https://bond-o.medium.com/golden-ticket-attack-ea89553cf9c0
- https://social.technet.microsoft.com/wiki/contents/articles/13813.localized-names-for-administrator-account-in-windows.aspx
- https://www.blackhat.com/docs/us-15/materials/us-15-Metcalf-Red-Vs-Blue-Modern-Active-Directory-Attacks-Detection-And-Protection-wp.pdf
tags:
- attack.credential_access
- attack.t1558.001
author: mdecrevoisier
status: stable
logsource:
  product: windows
  service: security
detection:
  selection:
    EventID: 4624
    TargetUserSid|endswith: '-500' # Refers to builtin Administrator SID account
    LogonProcessName: Kerberos
  filter:
    TargetUserName: # Excludes builtin admin account names when using a localized Windows OS version (select the ones applicable)
      - 'Administrator'  # Default
      - 'Järjestelmänvalvoja' # Finnish
      - 'Administrateur' # French
      - 'Administrador'  # Spanish / Portuguese
      - 'Administratör'  # Swedish
      - 'Rendszergazda'  # Hungarian
      - 'Администратор'  # Russian
  condition: selection and not filter
falsepositives:
- login with renamed builtin administrator account ("administrator" renamed to "admin_org")
level: high

Stages and Predicates

Stage 0: `condition`

selection and not filter

Stage 1: `selection`

selection:
  EventID: 4624
  TargetUserSid|endswith: '-500'
  LogonProcessName: Kerberos

Stage 2: `not filter`

filter:
  TargetUserName:
    - 'Administrator'
    - 'Järjestelmänvalvoja'
    - 'Administrateur'
    - 'Administrador'
    - 'Administratör'
    - 'Rendszergazda'
    - 'Администратор'

Exclusions

The rule actively suppresses these predicates.

Field	Kind	Excluded values	Search
`TargetUserName`	eq	`Administrador`	`excludes:TargetUserName` `field:"TargetUserName" value:"Administrador"`
`TargetUserName`	eq	`Administrateur`	`excludes:TargetUserName` `field:"TargetUserName" value:"Administrateur"`
`TargetUserName`	eq	`Administrator`	`excludes:TargetUserName` `field:"TargetUserName" value:"Administrator"`
`TargetUserName`	eq	`Administratör`	`excludes:TargetUserName` `field:"TargetUserName" value:"Administratör"`
`TargetUserName`	eq	`Järjestelmänvalvoja`	`excludes:TargetUserName` `field:"TargetUserName" value:"Järjestelmänvalvoja"`
`TargetUserName`	eq	`Rendszergazda`	`excludes:TargetUserName` `field:"TargetUserName" value:"Rendszergazda"`
`TargetUserName`	eq	`Администратор`	`excludes:TargetUserName` `field:"TargetUserName" value:"Администратор"`

Indicators

These rows show field, operator, and value matches.

Field	Kind	Values	Search
`LogonProcessName`	eq	`Kerberos`	`field:"LogonProcessName" kind:eq value:"Kerberos"`
`TargetUserSid`	ends_with	`-500` corpus 2 (sigma 2)	`field:"TargetUserSid" kind:ends_with value:"-500"`