Detection rules › Splunk

DNS Kerberos Coercion

Author
Raven Tait, Splunk
Source
upstream

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.

MITRE ATT&CK coverage

TacticTechniques
Credential AccessT1187 Forced Authentication, T1557.001 Adversary-in-the-Middle: LLMNR/NBT-NS Poisoning and SMB Relay
CollectionT1557.001 Adversary-in-the-Middle: LLMNR/NBT-NS Poisoning and SMB Relay
Command & ControlT1071.004 Application Layer Protocol: DNS

Event coverage

ProviderEvent IDTitle
Sysmon22DNSEvent (DNS query)

Stages and Predicates

Stage 1: tstats

tstats 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

Stage 2: search

search

Stage 3: search

search

Stage 4: search

search

Stage 5: table

table count, dest, firstTime, lastTime, query, src

Stage 6: search

search `macro`

Indicators

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.

FieldKindValues
DNS.queryeq
  • "*1UWhRC*"
  • "*AAAAA*"
  • "*YBAAAA*"