DNS Kerberos Coercion

 Original Source: [splunk source]
Name:DNS Kerberos Coercion
id:8551252d-b5b6-4b6e-8a82-51460aeb29a3
version:6
date:None
author:Raven Tait, Splunk
status:production
type:TTP
Description:Detects DNS-based Kerberos coercion attacks where adversaries inject marshaled credential structures into DNS records to spoof SPNs and redirect authentication such as in CVE-2025-33073. This detection leverages suricata looking for specific CREDENTIAL_TARGET_INFORMATION structures in DNS queries.
Data_source:
  • -Suricata
  • -Sysmon EventID 22
search:| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime values(DNS.src) as src values(DNS.dest) as dest FROM datamodel=Network_Resolution
WHERE DNS.query="*1UWhRC*" DNS.query="*AAAAA*" DNS.query="*YBAAAA*"
BY DNS.answer DNS.answer_count DNS.query
DNS.query_count DNS.reply_code_id DNS.src
DNS.vendor_product
| `drop_dm_object_name(DNS)`
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| table firstTime lastTime query count src dest
| `dns_kerberos_coercion_filter`


how_to_implement:To successfully implement this search, you will need to ensure that DNS data is populating the Network_Resolution data model.
known_false_positives:It's unlikely that a DNS entry contains the specific structure used by this attack. Filter as needed for your organization.
References:
  -https://web.archive.org/web/20250617122747/https://www.synacktiv.com/publications/ntlm-reflection-is-dead-long-live-ntlm-reflection-an-in-depth-analysis-of-cve-2025
  -https://www.synacktiv.com/publications/relaying-kerberos-over-smb-using-krbrelayx
  -https://www.guidepointsecurity.com/blog/the-birth-and-death-of-loopyticket/
drilldown_searches:
 name:'View the detection results for - "$src$"'
 search:'%original_detection_search% | search host = "$src$"'
 earliest_offset:'$info_min_time$'
 latest_offset:'$info_max_time$'
 name:'View risk events for the last 7 days for - "$src$"'
 search:'| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$src$") | stats count min(_time) as firstTime max(_time) as lastTime values(search_name) as "Search Name" values(risk_message) as "Risk Message" values(analyticstories) as "Analytic Stories" values(annotations._all) as "Annotations" values(annotations.mitre_attack.mitre_tactic) as "ATT&CK Tactics" by normalized_risk_object | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)`'
 earliest_offset:'7d'
 latest_offset:'0'
analytic_story:['Compromised Windows Host', 'Suspicious DNS Traffic', 'Local Privilege Escalation With KrbRelayUp', 'Kerberos Coercion with DNS']

asset_type:Endpoint

mitre_attack_id:['T1557.001', 'T1187', 'T1071.004']

product:['Splunk Enterprise', 'Splunk Enterprise Security', 'Splunk Cloud']

category:network

security_domain:network

tags:

tests:
 name:'True Positive Test'
 attack_data:
  data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1071.004/kerberos_coercion/suricata.log
  source: not_applicable
  sourcetype: suricata
  data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1071.004/kerberos_coercion/sysmon.log
  source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
  sourcetype: XmlWinEventLog
 test_type:'unit'
manual_test:None