Potential Kerberos SPN Spoofing via Suspicious DNS Query
Identifies queries for a DNS name containing a base64-encoded blob matching the pattern "UWhRCA...BAAAA". This pattern corresponds to a marshaled CREDENTIAL_TARGET_INFORMATION structure, commonly used in Kerberos…
Description
Identifies queries for a DNS name containing a base64-encoded blob matching the pattern "UWhRCA...BAAAA". This pattern corresponds to a marshaled CREDENTIAL_TARGET_INFORMATION structure, commonly used in Kerberos coercion attacks. It is associated with tools and techniques that exploit SPN spoofing via DNS. Adversaries may abuse such names to coerce victim systems into authenticating to attacker-controlled hosts while requesting Kerberos tickets for legitimate services (often the victim's own identity). Depending on the coerced service and negotiated authentication, this can support Kerberos relay or NTLM reflection/relay paths without relying on normal NTLM fallback behavior.
Detection logic
Its licence does not clear it for publishing here
Sunturai publishes a detection's own text where the licence it arrived under has been reviewed and permits it, and Elastic License 2.0 has not. The query as its source wrote it, its canonical form and the hash that pins this revision are in the workspace record.
Detection requirements
- Platform
- LinuxmacOSNetwork DevicesWindows
The rule states no platform. This is derived from the 2 ATT&CK techniques it maps to.
- Log source category
- event_index
MITRE ATT&CK mappings
0 exclusive techniques.This is coverage no other published rule has; it is not this rule's total technique count.
References
| Reference | Cited by |
|---|---|
| blog.redteam-pentesting.de/2025/reflective-kerberos-relay-attack/ | 3 |
| github.com/CICADA8-Research/RemoteKrbRelay/blob/main/README.md | 3 |
| github.com/Orange-Cyberdefense/ocd-mindmaps/blob/main/excalimap/mindmap/ad/authenticated.md | 4 |
| googleprojectzero.blogspot.com/2021/10/using-kerberos-for-authentication-relay.html | 9from 2 sources |
| www.synacktiv.com/en/publications/ntlm-reflection-is-dead-long-live-ntlm-reflection-an-in-depth-analysis-of-cve-2025.html | 2 |
From the source
- At source
- Open at source
- Upstream identifier
- 99ac5005-8a9e-4625-a0af-5f7bb447204b
- Tagged by the source as
- Data Source: CrowdstrikeData Source: Elastic DefendData Source: Elastic EndgameData Source: SentinelOneData Source: SysmonDomain: EndpointNoise: LowOS: WindowsPerformance: NormalPlatform: WindowsResources: Investigation GuideRule Type: Event Correlation (EQL)Tactic: Credential AccessUse Case: Threat Detection
Licence
- Published under
- Elastic License 2.0Read the licence
- Attribution
- Required
Authorship
- Written by
- Published
- Sep 20, 2026
- Version
- 3