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Description

The following analytic identifies the default service name created by KrbRelayUp. Defenders should be aware that attackers could change the hardcoded service name of the KrbRelayUp tool and bypass this detection.

  • Type: TTP
  • Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud

  • Last Updated: 2022-05-02
  • Author: Michael Haag, Splunk
  • ID: e40ef542-8241-4419-9af4-6324582ea60a

Annotations

ATT&CK

ATT&CK

ID Technique Tactic
T1543.003 Windows Service Persistence, Privilege Escalation
Kill Chain Phase
  • Installation
  • Exploitation
NIST
  • DE.CM
CIS20
  • CIS 10
CVE
1
2
3
4
5
`wineventlog_system` EventCode=7045 Service_Name IN ("KrbSCM") 
| stats count min(_time) as firstTime max(_time) as lastTime by dest EventCode Service_File_Name Service_Name Service_Start_Type Service_Type 
| `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)` 
| `windows_krbrelayup_service_creation_filter`

Macros

The SPL above uses the following Macros:

:information_source: windows_krbrelayup_service_creation_filter is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Required fields

List of fields required to use this analytic.

  • _time
  • EventCode
  • Service_File_Name
  • Service_Name
  • Service_Start_Type
  • Service_Type

How To Implement

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

RBA

Risk Score Impact Confidence Message
64.0 80 80 A service was created on $dest$, related to KrbRelayUp.

:information_source: The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.

Reference

Test Dataset

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 | version: 1