ID | Technique | Tactic |
---|---|---|
T1098 | Account Manipulation | Persistence |
Detection: Windows AD ServicePrincipalName Added To Domain Account
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.
Search
1`wineventlog_security` EventCode=5136 AttributeLDAPDisplayName=servicePrincipalName OperationType="%%14674"
2| stats values(ObjectDN) as ObjectDN by _time, Computer, SubjectUserName, AttributeValue
3| rename Computer as dest SubjectUserName as user
4| `windows_ad_serviceprincipalname_added_to_domain_account_filter`
Data Source
Name | Platform | Sourcetype | Source | Supported App |
---|---|---|---|---|
Windows Event Log Security 5136 | Windows | 'xmlwineventlog' |
'XmlWinEventLog:Security' |
N/A |
Macros Used
Name | Value |
---|---|
wineventlog_security | eventtype=wineventlog_security OR Channel=security OR source=XmlWinEventLog:Security |
windows_ad_serviceprincipalname_added_to_domain_account_filter | search * |
windows_ad_serviceprincipalname_added_to_domain_account_filter
is an empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.
Annotations
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 |
Implementation
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
Risk Based Analytics (RBA)
Risk Message | Risk Score | Impact | Confidence |
---|---|---|---|
A Servince Principal Name for $ObjectDN$ was set by $user$ | 30 | 60 | 50 |
References
-
https://www.thehacker.recipes/ad/movement/dacl/targeted-kerberoasting
-
https://learn.microsoft.com/en-us/windows/security/threat-protection/auditing/event-5136
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: 4