Sigma rule: Suspicious DNS Query Indicating Kerberos Coercion via DNS Object SPN Spoofing - Network

A detection rule from the SigmaHQ repository, shown as its author published it. Dataset version ref-bf8f0a9d58a9, updated 2025-06-20T00:00:00.000Z.

Rule

Title
Suspicious DNS Query Indicating Kerberos Coercion via DNS Object SPN Spoofing - Network
Status
experimental
Level
high
Author
Swachchhanda Shrawan Poudel (Nextron Systems)
Date
2025-06-20
File
rules/network/zeek/zeek_dns_kerberos_coercion_via_dns_object_spn_spoofing.yml
Commit
ccbb0369507f796db0b0ae6854c8a2be471b9d84

Detects DNS queries containing patterns associated with Kerberos coercion attacks via DNS object spoofing.
The pattern "1UWhRCAAAAA..BAAAA" is a base64-encoded signature that corresponds to a marshaled CREDENTIAL_TARGET_INFORMATION structure.
Attackers can use this technique to coerce authentication from victim systems to attacker-controlled hosts.
It is one of the strong indicators of a Kerberos coercion attack, where adversaries manipulate DNS records
to spoof Service Principal Names (SPNs) and redirect authentication requests like CVE-2025-33073.

Log source

product
zeek
service
dns

Detection

selection:
    query|contains|all:
        - 'UWhRCA' # Follows this pattern UWhRCAAAAA..BAAA
        - 'BAAAA'
condition: selection

False positives (as the rule lists them)

  • Unknown

Tags

  • attack.collection
  • attack.credential-access
  • attack.persistence
  • attack.privilege-escalation
  • attack.t1557.001
  • attack.t1187

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/network/zeek/zeek_dns_kerberos_coercion_via_dns_object_spn_spoofing.yml

Sources and licences

  • SigmaHQ

    "Suspicious DNS Query Indicating Kerberos Coercion via DNS Object SPN Spoofing - Network" by Swachchhanda Shrawan Poudel (Nextron Systems) (SigmaHQ). Rule: https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules/network/zeek/zeek_dns_kerberos_coercion_via_dns_object_spn_spoofing.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: Suspicious DNS Query Indicating Kerberos Coercion via DNS Object SPN Spoofing - Network",
entity page, dataset version ref-bf8f0a9d58a9, updated 2025-06-20T00:00:00.000Z,
https://ransomware-tracker.com/detections/sigma/5588576c-5898-4fac-bcdd-7475a60e8f43 (accessed 2026-11-03).
Underlying source: SigmaHQ rule 5588576c-5898-4fac-bcdd-7475a60e8f43, 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.