Sigma rule: Kerberos Network Traffic RC4 Ticket Encryption

A detection rule from the SigmaHQ repository, shown as its author published it. Dataset version ref-e99175eee047, updated 2021-11-27T00:00:00.000Z.

Rule

Title
Kerberos Network Traffic RC4 Ticket Encryption
Status
test
Level
medium
Author
sigma
Date
2020-02-12
Modified
2021-11-27
File
rules/network/zeek/zeek_susp_kerberos_rc4.yml
Commit
ccbb0369507f796db0b0ae6854c8a2be471b9d84

Detects kerberos TGS request using RC4 encryption which may be indicative of kerberoasting

Log source

product
zeek
service
kerberos

Detection

selection:
    request_type: 'TGS'
    cipher: 'rc4-hmac'
computer_acct:
    service|startswith: '$'
condition: selection and not computer_acct

False positives (as the rule lists them)

  • Normal enterprise SPN requests activity

Tags

  • attack.credential-access
  • attack.t1558.003

MITRE ATT&CK ids this rule names

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/network/zeek/zeek_susp_kerberos_rc4.yml

Sources and licences

  • SigmaHQ

    "Kerberos Network Traffic RC4 Ticket Encryption" by sigma (SigmaHQ). Rule: https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules/network/zeek/zeek_susp_kerberos_rc4.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: Kerberos Network Traffic RC4 Ticket Encryption",
entity page, dataset version ref-e99175eee047, updated 2021-11-27T00:00:00.000Z,
https://ransomware-tracker.com/detections/sigma/503fe26e-b5f2-4944-a126-eab405cc06e5 (accessed 2026-11-03).
Underlying source: SigmaHQ rule 503fe26e-b5f2-4944-a126-eab405cc06e5, 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.