ID | Technique | Tactic |
---|---|---|
T1098 | Account Manipulation | Persistence |
Detection: Windows AD Short Lived Domain Account ServicePrincipalName
Description
The following analytic identifies the addition and quick deletion of a Service Principal Name (SPN) to a domain account within 5 minutes. This detection leverages EventCode 5136 from the Windows Security Event Log, focusing on changes to the servicePrincipalName attribute. This activity is significant as it may indicate an attempt to perform Kerberoasting, a technique used to crack the cleartext password of a domain account offline. If confirmed malicious, this could allow an attacker to gain unauthorized access to sensitive information or escalate privileges within the domain environment.
Search
1`wineventlog_security` EventCode=5136 AttributeLDAPDisplayName=servicePrincipalName
2| transaction ObjectDN AttributeValue startswith=(EventCode=5136 OperationType="%%14674") endswith=(EventCode=5136 OperationType="%%14675")
3| eval short_lived=case((duration<300),"TRUE")
4| search short_lived = TRUE
5| rename ObjectDN as user
6| `windows_ad_short_lived_domain_account_serviceprincipalname_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_short_lived_domain_account_serviceprincipalname_filter | search * |
windows_ad_short_lived_domain_account_serviceprincipalname_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. Adding an SPN and quickly deleting it is less common but may be part of legitimate action. Filter as needed.
Associated Analytic Story
Risk Based Analytics (RBA)
Risk Message | Risk Score | Impact | Confidence |
---|---|---|---|
A Servince Principal Name for $user$ was set and shortly deleted | 40 | 50 | 80 |
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: 3