Unusual Outbound Kerberos Connection - Security (via security)

title: Unusual Outbound Kerberos Connection - Security (via security)
id: 59025df1-7349-5cb4-bfee-2017c2bb0100
status: stable
description: This rule detects uncommon outbound network behavior via Kerberos default port suggesting possible lateral movement or first stage PrivEsc via delegation.
references:
    - https://attack.mitre.org/techniques/T1558/003/
    - https://github.com/GhostPack/Rubeus
author: Huntrule Team
date: 2026-04-14
tags:
    - attack.lateral-movement
    - attack.credential-access
    - attack.t1558.003
logsource:
    product: windows
    service: security
detection:
    selection:
        EventID: 5156
        DestPort: 88
    filter_main_lsass:
        Application|startswith:
            - '\device\harddiskvolume'
            - 'C:'
        Application|endswith: '\Windows\System32\lsass.exe'
    filter_optional_chrome:
        Application|startswith:
            - '\device\harddiskvolume'
            - 'C:'
        Application|endswith:
            - '\Program Files (x86)\Google\Chrome\Application\chrome.exe'
            - '\Program Files\Google\Chrome\Application\chrome.exe'
    filter_optional_firefox:
        Application|startswith:
            - '\device\harddiskvolume'
            - 'C:'
        Application|endswith:
            - '\Program Files (x86)\Mozilla Firefox\firefox.exe'
            - '\Program Files\Mozilla Firefox\firefox.exe'
    filter_optional_tomcat:
        Application|endswith: '\tomcat\bin\tomcat8.exe'
    filter_hr:
        Application|startswith:
            - \device\harddiskvolume
            - 'C:'
        Application|endswith:
            - \Program Files (x86)\Microsoft\Edge\Application\msedge.exe
            - \Program Files\Microsoft\Edge\Application\msedge.exe
    condition: (selection and not 1 of filter_main_* and not 1 of filter_optional_*) and not filter_hr
falsepositives:
    - Unknown
level: medium