Try in Splunk Security Cloud

Description

The following analytic detects the addition of a Service Principal Name (SPN) to a domain account. It leverages Windows Event Code 5136 and monitors changes to the servicePrincipalName attribute. This activity is significant because it may indicate an attempt to perform Kerberoasting, a technique where attackers extract and crack service account passwords offline. If confirmed malicious, this could allow an attacker to obtain cleartext passwords, leading to unauthorized access and potential lateral movement within the domain environment.

  • Type: TTP

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

  • Last Updated: 2024-05-22
  • Author: Mauricio Velazco, Splunk
  • ID: 8a1259cb-0ea7-409c-8bfe-74bad89259f9

Annotations

ATT&CK

ATT&CK

ID Technique Tactic
T1098 Account Manipulation Persistence, Privilege Escalation
Kill Chain Phase
  • Installation
  • Exploitation
NIST
  • DE.CM
CIS20
  • CIS 10
CVE 


1
2
3
4



 `wineventlog_security` EventCode=5136 AttributeLDAPDisplayName=servicePrincipalName OperationType="%%14674" 
| stats values(ObjectDN) as ObjectDN by _time, Computer, SubjectUserName, AttributeValue 
| rename Computer as dest SubjectUserName as user 
| `windows_ad_serviceprincipalname_added_to_domain_account_filter`

Macros

The SPL above uses the following Macros:

:information_source: windows_ad_serviceprincipalname_added_to_domain_account_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
  • ObjectDN
  • signature
  • SubjectUserName
  • Computer

How To Implement

To successfully implement this search, you ned to be ingesting eventcode 5136. The Advanced Security Audit policy setting Audit Directory Services Changes within DS Access needs to be enabled. Additionally, a SACL needs to be created for AD objects in order to ingest attribute modifications.

Known False Positives

A Service Principal Name should only be added to an account when an application requires it. While infrequent, this detection may trigger on legitimate actions. Filter as needed.

Associated Analytic Story

RBA

Risk Score Impact Confidence Message
30.0 60 50 A Servince Principal Name for $ObjectDN$ was set by $user$

: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: 3