Detection: Windows Admon Group Policy Object Created

Updated Date: 2024-09-30 ID: 69201633-30d9-48ef-b1b6-e680805f0582 Author: Mauricio Velazco, Splunk Type: TTP Product: Splunk Enterprise Security

Description

The following analytic detects the creation of a new Group Policy Object (GPO) using Splunk's Admon data. It identifies events where a new GPO is created, excluding default "New Group Policy Object" entries. Monitoring GPO creation is crucial as adversaries can exploit GPOs to escalate privileges or deploy malware across an Active Directory network. If confirmed malicious, this activity could allow attackers to control system configurations, deploy ransomware, or propagate malware, significantly compromising the network's security.

1`admon` admonEventType=Update objectCategory="CN=Group-Policy-Container,CN=Schema,CN=Configuration,DC=*" versionNumber=0 displayName!="New Group Policy Object" 
2| stats min(_time) as firstTime max(_time) as lastTime values(gPCFileSysPath) by dcName, displayName 
3| `security_content_ctime(firstTime)` 
4| `security_content_ctime(lastTime)` 
5| `windows_admon_group_policy_object_created_filter`

Data Source

Name Platform Sourcetype Source
Windows Active Directory Admon Windows icon Windows 'ActiveDirectory' 'ActiveDirectory'

Macros Used

Name Value
admon source=ActiveDirectory
windows_admon_group_policy_object_created_filter search *
windows_admon_group_policy_object_created_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
T1484 Domain or Tenant Policy Modification Defense Evasion
T1484.001 Group Policy Modification Privilege Escalation
KillChainPhase.EXPLOITAITON
NistCategory.DE_CM
Cis18Value.CIS_10
APT41
Cinnamon Tempest
Indrik Spider

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
This configuration file applies to all detections of type TTP. These detections will use Risk Based Alerting and generate Notable Events.

Implementation

To successfully implement this search, you need to be monitoring Active Directory logs using Admon. Details can be found here https://docs.splunk.com/Documentation/SplunkCloud/8.1.2101/Data/MonitorActiveDirectory

Known False Positives

Group Policy Objects are created as part of regular administrative operations, filter as needed.

Associated Analytic Story

Risk Based Analytics (RBA)

Risk Message Risk Score Impact Confidence
A new group policy objected was created on $dcName$ 50 100 50
The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.

References

Detection Testing

Test Type Status Dataset Source Sourcetype
Validation ✅ Passing N/A N/A N/A
Unit ✅ Passing Dataset ActiveDirectory ActiveDirectory
Integration ✅ Passing Dataset ActiveDirectory ActiveDirectory

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