Sigma Rule Library

Uncommon Outbound Kerberos Connection

Detects uncommon outbound network activity via Kerberos default port indicating possible lateral movement or first stage PrivEsc via delegation.

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Detection logic

selection

DestinationPort: 88
Initiated: "true"

filter_main_lsass

Image: C:\Windows\System32\lsass.exe

filter_optional_chrome

Image:
  - C:\Program Files (x86)\Google\Chrome\Application\chrome.exe
  - C:\Program Files\Google\Chrome\Application\chrome.exe

filter_optional_firefox

Image:
  - C:\Program Files (x86)\Mozilla Firefox\firefox.exe
  - C:\Program Files\Mozilla Firefox\firefox.exe

filter_optional_tomcat

Image|endswith: \tomcat\bin\tomcat8.exe

Condition

selection and not 1 of filter_main_* and not 1 of filter_optional_*

Raw YAML

title: Uncommon Outbound Kerberos Connection
id: e54979bd-c5f9-4d6c-967b-a04b19ac4c74
related:
    - id: eca91c7c-9214-47b9-b4c5-cb1d7e4f2350
      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.credential-access
    - attack.t1558
    - attack.lateral-movement
    - attack.t1550.003
logsource:
    category: network_connection
    product: windows
detection:
    selection:
        DestinationPort: 88
        Initiated: 'true'
    filter_main_lsass:
        Image: 'C:\Windows\System32\lsass.exe'
    filter_optional_chrome:
        Image:
            - 'C:\Program Files (x86)\Google\Chrome\Application\chrome.exe'
            - 'C:\Program Files\Google\Chrome\Application\chrome.exe'
    filter_optional_firefox:
        Image:
            - 'C:\Program Files (x86)\Mozilla Firefox\firefox.exe'
            - 'C:\Program Files\Mozilla Firefox\firefox.exe'
    filter_optional_tomcat:
        Image|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

False positives

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

References

Similar rules