| ID | Technique | Tactic |
|---|---|---|
| T1562.001 | Disable or Modify Tools | Defense Evasion |
| T1484.001 | Group Policy Modification | Defense Evasion |
Detection: Windows AD GPO Deleted
Description
This detection identifies when an Active Directory Group Policy is deleted using the Group Policy Management Console.
Search
1`wineventlog_security` EventCode=5136 AttributeLDAPDisplayName=gpLink
2| eval ObjectDN=upper(ObjectDN)
3| stats min(_time) as eventTime values(eval(if(OperationType=="%%14675",AttributeValue,null))) as old_value values(eval(if(OperationType=="%%14674",AttributeValue,null))) as new_value values(OperationType) as OperationType values(src_user) as src_user by OpCorrelationID ObjectDN SubjectLogonId
4| rex field=old_value max_match=10000 "(?i)LDAP://(?P<old_dn>cn.*?);(?P<old_flag>\d)\]"
5| rex field=new_value max_match=10000 "(?i)LDAP://(?P<new_dn>cn.*?);(?P<new_flag>\d)\]"
6| mvexpand old_dn
7| where NOT old_dn IN (new_dn)
8| eval ObjectDN=upper(old_dn)
9| join ObjectDN type=outer [
10| search `admon` objectCategory="CN=Group-Policy-Container*" admonEventType=Update
11| eval ObjectDN=upper(distinguishedName)
12| stats latest(displayName) as displayName by ObjectDN ]
13| stats min(eventTime) as _time values(OpCorrelationID) as OpCorrelationID values(displayName) as policyName values(src_user) as src_user by ObjectDN SubjectLogonId
14| `windows_ad_gpo_deleted_filter`
Data Source
| Name | Platform | Sourcetype | Source | Supported App |
|---|---|---|---|---|
| N/A | N/A | N/A | N/A | N/A |
Macros Used
| Name | Value |
|---|---|
| admon | source=ActiveDirectory |
| windows_ad_gpo_deleted_filter | search * |
windows_ad_gpo_deleted_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
KillChainPhase.EXPLOITAITON
NistCategory.DE_CM
Cis18Value.CIS_10
Aquatic Panda
BRONZE BUTLER
Ember Bear
FIN6
Gamaredon Group
Gorgon Group
Indrik Spider
Kimsuky
Lazarus Group
Magic Hound
MuddyWater
Putter Panda
Rocke
TA2541
TA505
TeamTNT
Turla
Wizard Spider
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
Ensure you are ingesting Active Directory audit logs - specifically event 5136, admon data is also used to display the display name of the GPO. See lantern article in references for further on how to onboard AD audit data. Ensure the wineventlog_security and admon macros are configured with the correct indexes.
Known False Positives
Unknown
Associated Analytic Story
Risk Based Analytics (RBA)
| Risk Message | Risk Score | Impact | Confidence |
|---|---|---|---|
| GPO $policyName$ was deleted by $src_user$ | 64 | 80 | 80 |
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 | 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: 1