Sigma rule: Uncommon Outbound Kerberos Connection

A detection rule from the SigmaHQ repository, shown as its author published it. Dataset version ref-2f5f8a53f6ed, updated 2024-03-15T00:00:00.000Z.

Rule

Title
Uncommon Outbound Kerberos Connection
Status
test
Level
medium
Author
Ilyas Ochkov, oscd.community
Date
2019-10-24
Modified
2024-03-15
File
rules/windows/network_connection/net_connection_win_susp_outbound_kerberos_connection.yml
Commit
ccbb0369507f796db0b0ae6854c8a2be471b9d84

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

Log source

product
windows
category
network_connection

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_*

False positives (as the rule lists them)

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

Tags

  • attack.credential-access
  • attack.t1558
  • attack.lateral-movement
  • attack.t1550.003

MITRE ATT&CK ids this rule names

Related rules

References

Read on 2026-11-03T00:58:21.399Z under licence sigma-drl-1.1@d5f4c36a from https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules/windows/network_connection/net_connection_win_susp_outbound_kerberos_connection.yml

Sources and licences

  • SigmaHQ

    "Uncommon Outbound Kerberos Connection" by Ilyas Ochkov, oscd.community (SigmaHQ). Rule: https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules/windows/network_connection/net_connection_win_susp_outbound_kerberos_connection.yml.
    Licensed under the Detection Rule License (DRL) 1.1: https://github.com/SigmaHQ/Detection-Rule-License

    Detection Rule License (DRL) 1.1

Cite this page

Dragons Eye Ransomware Tracker, "Sigma rule: Uncommon Outbound Kerberos Connection",
entity page, dataset version ref-2f5f8a53f6ed, updated 2024-03-15T00:00:00.000Z,
https://ransomware-tracker.com/detections/sigma/e54979bd-c5f9-4d6c-967b-a04b19ac4c74 (accessed 2026-11-03).
Underlying source: SigmaHQ rule e54979bd-c5f9-4d6c-967b-a04b19ac4c74, commit ccbb0369507f796db0b0ae6854c8a2be471b9d84.

Pages change. The dataset version identifies the data, but no archive of old versions is kept, so this citation cannot be replayed later.