sigmamediumHunting

Suspicious Kerberos RC4 Ticket Encryption

Detects service ticket requests using RC4 encryption type

MITRE ATT&CK

credential-access

Detection Query

selection:
  EventID: 4769
  TicketOptions: "0x40810000"
  TicketEncryptionType: "0x17"
reduction:
  ServiceName|endswith: $
condition: selection and not reduction

Author

Florian Roth (Nextron Systems)

Created

2017-02-06

Data Sources

windowssecurity

Platforms

windows

References

Tags

attack.credential-accessattack.t1558.003

Raw Content

title: Suspicious Kerberos RC4 Ticket Encryption
id: 496a0e47-0a33-4dca-b009-9e6ca3591f39
status: test
description: Detects service ticket requests using RC4 encryption type
references:
    - https://adsecurity.org/?p=3458
    - https://www.trimarcsecurity.com/single-post/TrimarcResearch/Detecting-Kerberoasting-Activity
author: Florian Roth (Nextron Systems)
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