Sigma rule: Attempts of Kerberos Coercion Via DNS SPN Spoofing

A detection rule from the SigmaHQ repository, shown as its author published it. Dataset version ref-0da14482b00e, updated 2025-06-20T00:00:00.000Z.

Rule

Title
Attempts of Kerberos Coercion Via DNS SPN Spoofing
Status
experimental
Level
high
Author
Swachchhanda Shrawan Poudel (Nextron Systems)
Date
2025-06-20
File
rules/windows/process_creation/proc_creation_win_kerberos_coercion_via_dns_spn_spoofing.yml
Commit
ccbb0369507f796db0b0ae6854c8a2be471b9d84

Detects the presence of "UWhRC....AAYBAAAA" pattern in command line.
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 in CVE-2025-33073.
If you see this pattern in the command line, it is likely an attempt to add spoofed Service Principal Names (SPNs) to DNS records,
or checking for the presence of such records through the `nslookup` command.

Log source

product
windows
category
process_creation

Detection

selection:
    CommandLine|contains|all:
        - 'UWhRCA'
        - '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/windows/process_creation/proc_creation_win_kerberos_coercion_via_dns_spn_spoofing.yml

Sources and licences

  • SigmaHQ

    "Attempts of Kerberos Coercion Via DNS SPN Spoofing" by Swachchhanda Shrawan Poudel (Nextron Systems) (SigmaHQ). Rule: https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules/windows/process_creation/proc_creation_win_kerberos_coercion_via_dns_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: Attempts of Kerberos Coercion Via DNS SPN Spoofing",
entity page, dataset version ref-0da14482b00e, updated 2025-06-20T00:00:00.000Z,
https://ransomware-tracker.com/detections/sigma/0ed99dda-6a35-11ef-8c99-0242ac120002 (accessed 2026-11-03).
Underlying source: SigmaHQ rule 0ed99dda-6a35-11ef-8c99-0242ac120002, 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.