Uncommon Outbound Kerberos Connection - Security — Sigma Rule

Rule metadata and linked tags

Author: Ilyas Ochkov, oscd.community. Source status: test; severity: medium. Source dates: 2019-10-24 / 2024-03-15.

{
  "product": "windows",
  "service": "security"
}

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: 11da4d56d7adb8f012cb18bae1ac3fa9eb2812c1fabf0ef0592961e72ca722ce

Detection logic

Original source YAML. Source-tag agreement is not proof of complete semantic coverage. This rule has not been compiled for a SIEM backend or validated against live telemetry here.

title: Uncommon Outbound Kerberos Connection - Security
id: eca91c7c-9214-47b9-b4c5-cb1d7e4f2350
related:
    - id: e54979bd-c5f9-4d6c-967b-a04b19ac4c74
      type: similar
status: test
description: |
    Detects uncommon outbound network activity via Kerberos default port indicating possible lateral movement or first stage PrivEsc via delegation.
references:
    - https://github.com/GhostPack/Rubeus
author: Ilyas Ochkov, oscd.community
date: 2019-10-24
modified: 2024-03-15
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'
    condition: selection and not 1 of filter_main_* and not 1 of filter_optional_*
falsepositives:
    - Web Browsers and third party application might generate similar activity. An initial baseline is required.
level: medium

Original YAML and metadata in JSON

False positives

• Web Browsers and third party application might generate similar activity. An initial baseline is required.

Source references

• https://github.com/GhostPack/Rubeus