Windows Kerberos Service Tickets Requesting RC4 Encryption (EventID 4769)

Flags Windows Kerberos service ticket requests using RC4 encryption while excluding '$' machine/service accounts.

FreeReviewedSigma · Medium · v2
Product
windows
Service
security
Author
Florian Roth (Nextron Systems) (SigmaHQ), DRL 1.1
Published
2017-02-06
Updated
2026-07-31
title: Windows Kerberos Service Tickets Requesting RC4 Encryption (EventID 4769)
id: 58859774-b359-4a62-b0f9-6c8d5b39c4c5
status: test
description: This rule flags Kerberos service ticket requests that specify RC4 as the ticket encryption type and match a particular TicketOptions value. Attackers may use weaker or targeted encryption settings to facilitate credential access attempts such as offline cracking of extracted ticket material. It relies on Windows Security auditing telemetry for EventID 4769, including TicketOptions, TicketEncryptionType, and ServiceName to suppress likely benign machine-account behavior.
references:
  - https://adsecurity.org/?p=3458
  - https://www.trimarcsecurity.com/single-post/TrimarcResearch/Detecting-Kerberoasting-Activity
  - https://github.com/SigmaHQ/sigma/blob/master/rules/windows/builtin/security/win_security_susp_rc4_kerberos.yml
author: Florian Roth (Nextron Systems), Huntrule Team
date: 2017-02-06
modified: 2022-06-19
tags:
  - attack.credential-access
  - attack.t1558.003
logsource:
  product: windows
  service: security
detection:
  selection:
    EventID: 4769
    TicketOptions: "0x40810000"
    TicketEncryptionType: "0x17"
  reduction:
    ServiceName|endswith: $
  condition: selection and not reduction
falsepositives:
  - Service accounts used on legacy systems (e.g. NetApp)
  - Windows Domains with DFL 2003 and legacy systems
level: medium
license: DRL-1.1
related:
  - id: 496a0e47-0a33-4dca-b009-9e6ca3591f39
    type: derived