Detection rules › Splunk
Windows AD GPO New CSE Addition
This detection identifies when a a new client side extension is added to an Active Directory Group Policy using the Group Policy Management Console.
MITRE ATT&CK coverage
Event coverage
| Provider | Event ID | Title |
|---|---|---|
| Security-Auditing | 5136 | A directory service object was modified. |
Stages and Predicates
Stage 1: search
search AttributeLDAPDisplayName="gPCMachineExtensionNames" EventCode=5136 ObjectClass="groupPolicyContainer"
Stage 2: stats
stats BY ObjectClass, ObjectDN, OpCorrelationID, src_user, SubjectLogonId
Stage 3: rex
rex field=old_value ...
Stage 4: rex
rex field=new_value ...
Stage 5: rex
rex field=ObjectDN ...
Stage 6: mvexpand
mvexpand
Stage 7: where
where NOT new_values IN ("{00000000-0000-0000-0000-000000000000}", "old_values", "policy_guid") new_values="^\{[A-Z | \d]+\-[A-Z | \d]+\-[A-Z | \d]+\-[A-Z | \d]+\-[A-Z | \d]+\}"
Stage 8: lookup
lookup <lookup> displayName, guid, new_values, policyType
Stage 9: eval
eval ... using (new_values, policyType)
Stage 10: join
join type=inner (...)
Stage 11: stats
stats BY ObjectDN
Stage 12: search
search `macro`
Exclusions
Top-level NOT(...) conjuncts — predicates this rule actively suppresses.
| Stage | Field | Kind | Excluded values |
|---|---|---|---|
| 1 | new_values | in | "{00000000-0000-0000-0000-000000000000}", old_values, policy_guid |
Indicators
Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.
| Field | Kind | Values |
|---|---|---|
AttributeLDAPDisplayName | eq |
|
EventCode | eq |
|
ObjectClass | eq |
|
admonEventType | eq |
|
new_values | match |
|
objectCategory | eq |
|
Neighbors
Broader alternatives (more inclusive than this rule)
These rules match a superset of what this rule catches. They cover the same events plus more. Use them if you want wider coverage and can absorb more false positives.
- Windows AD Dangerous Deny ACL Modification (drops 2 filters this rule applies)
- Windows AD Object Owner Updated (drops 2 filters this rule applies)
- Windows AD Self DACL Assignment (drops 2 filters this rule applies)