GitHub Repo

Detection: Windows KrbRelayUp Service Creation

Updated Date: 2026-05-13 ID: e40ef542-8241-4419-9af4-6324582ea60a Author: Michael Haag, Splunk Type: TTP Product: Splunk Enterprise Security

Description

The following analytic detects the creation of a service with the default name "KrbSCM" associated with the KrbRelayUp tool. It leverages Windows System Event Logs, specifically EventCode 7045, to identify this activity. This behavior is significant as KrbRelayUp is a known tool used for privilege escalation attacks. If confirmed malicious, this activity could allow an attacker to escalate privileges, potentially gaining unauthorized access to sensitive systems and data.

 1`wineventlog_system` EventCode=7045 ServiceName IN ("KrbSCM")
 2  
 3| stats count min(_time) as firstTime max(_time) as lastTime
 4    BY dest EventCode ImagePath
 5       ServiceName StartType ServiceType
 6  
 7| `security_content_ctime(firstTime)`
 8  
 9| `security_content_ctime(lastTime)`
10  
11| `windows_krbrelayup_service_creation_filter`

Data Source

Name Platform Sourcetype Source
Windows Event Log System 7045 Windows icon Windows 'XmlWinEventLog' 'XmlWinEventLog:System'

Macros Used

Name Value
wineventlog_system eventtype="wineventlog_system" OR Channel="system" OR source="XmlWinEventLog:System" OR source="WinEventLog:System"
windows_krbrelayup_service_creation_filter search *
windows_krbrelayup_service_creation_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
T1543.003 Windows Service Persistence
Exploitation
Installation
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 Finding (Notable) Yes
Rule Title %name%
Rule Description %description%
Notable Event Fields user, dest
Creates Intermediate Finding (Risk Event) No
TTP detections generate a Finding (Notable) and may generate Intermediate Findings (Risk Events) for associated entities.

Implementation

To successfully implement this search, you need to be ingesting Windows System Event Logs with 7045 EventCode enabled. The Windows TA is also required.

Known False Positives

False positives should be limited as this is specific to KrbRelayUp based attack. Filter as needed.

Associated Analytic Story

Finding

Title Entity Field Entity Type Risk Score
A service was created on $dest$, related to KrbRelayUp. dest system 50

References

Detection Testing

Test Type Status Dataset Source Sourcetype
Validation ✅ Passing N/A N/A N/A
Unit ✅ Passing Dataset XmlWinEventLog:System XmlWinEventLog
Integration ✅ Passing Dataset XmlWinEventLog:System 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: 11