Detection: Windows Kerberos Coercion via DNS

Updated Date: 2025-11-12 ID: 9029b575-6f6b-4ab1-b660-67b24b7e9c3d Author: Raven Tait, Splunk Type: TTP Product: Splunk Enterprise Security

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 Windows Security Event Codes 5136, 5137, 4662, looking for DNS events with specific CREDENTIAL_TARGET_INFORMATION entries.

Search

1`wineventlog_security`  (((EventCode="5136" OR EventCode="5137") ObjectClass="dnsNode" ObjectDN="*1UWhRCA*" ObjectDN="*AAAAA*" ObjectDN="*YBAAAA*") OR (EventCode="4662" AdditionalInfo="*1UWhRCA*" AdditionalInfo="*AAAAA*" AdditionalInfo="*YBAAAA*")) 
2| eval Object=coalesce(lower(ObjectGUID), trim(AdditionalInfo2, "%{}")) 
3| eval user=coalesce(SubjectUserName, Caller_User_Name) 
4| stats min(_time) as firstTime, max(_time) as lastTime values(EventCode) as event_codes values(ObjectDN) as dns_record values(user) as user values(Computer) as dest by Object 
5| `security_content_ctime(firstTime)` 
6| `security_content_ctime(lastTime)` 
7| `windows_kerberos_coercion_via_dns_filter`

Data Source

Name	Platform	Sourcetype	Source
Windows Event Log Security 4662	Windows	`'XmlWinEventLog'`	`'XmlWinEventLog:Security'`
Windows Event Log Security 5136	Windows	`'XmlWinEventLog'`	`'XmlWinEventLog:Security'`
Windows Event Log Security 5137	Windows	`'XmlWinEventLog'`	`'XmlWinEventLog:Security'`

Macros Used

Name	Value
security_content_ctime	`convert timeformat="%Y-%m-%dT%H:%M:%S" ctime($field$)`
windows_kerberos_coercion_via_dns_filter	`search *`

windows_kerberos_coercion_via_dns_filter is an empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Annotations

- MITRE ATT&CK

+ Kill Chain Phases

+ NIST

+ CIS

- Threat Actors

ID	Technique	Tactic
T1071.004	DNS	Command And Control
T1557.001	LLMNR/NBT-NS Poisoning and SMB Relay	Collection
T1187	Forced Authentication	Credential Access

Command and Control

Exploitation

DE.CM

CIS 10

Default Configuration

This detection is configured by default in Splunk Enterprise Security to run with the following settings:

Setting	Value
Disabled	true
Cron Schedule	`0 * * * *`
Earliest Time	`-70m@m`
Latest Time	`-10m@m`
Schedule Window	`auto`
Creates Notable	Yes
Rule Title	`%name%`
Rule Description	`%description%`
Notable Event Fields	user, dest
Creates Risk Event	True

This configuration file applies to all detections of type TTP. These detections will use Risk Based Alerting and generate Notable Events.

Implementation

To successfully implement this search, you ned to be ingesting Event codes 4662, 5136, 5137. The Advanced Security Audit policy setting Audit Directory Services Changes within DS Access needs to be enabled. For these event codes to be generated, specific SACLs are required.

Known False Positives

Creating a DNS entry matching this pattern is very unusual in a production environment. Filter as needed.

Associated Analytic Story

Risk Based Analytics (RBA)

Risk Message:

A possible Kerberos coercion DNS object was created $dest$

Risk Object	Risk Object Type	Risk Score	Threat Objects
dest	system	74	No Threat Objects
user	user	74	No Threat Objects

References

Detection Testing

Test Type	Status	Dataset	Source	Sourcetype
Validation	✅ Passing	N/A	N/A	N/A
Unit	✅ Passing	Dataset	`XmlWinEventLog:Security`	`XmlWinEventLog`
Integration	✅ Passing	Dataset	`XmlWinEventLog:Security`	`XmlWinEventLog`

Replay any dataset to Splunk Enterprise by using our replay.py tool or the UI. Alternatively you can replay a dataset into a Splunk Attack Range

Source: GitHub | Version: 1