Detection rules › Splunk

Windows Increase in Group or Object Modification Activity

Status
production
Severity
medium
Group by
_time, signature, status, user
Author
Dean Luxton
Source
github.com/splunk/security_content

This analytic detects an increase in modifications to AD groups or objects. Frequent changes to AD groups or objects can indicate potential security risks, such as unauthorized access attempts, impairing defences or establishing persistence. By monitoring AD logs for unusual modification patterns, this detection helps identify suspicious behavior that could compromise the integrity and security of the AD environment.

Known false positives

  • No false positives have been identified at this time.

MITRE ATT&CK coverage

TacticTechniques
Persistence
Privilege Escalation
Defense Impairment

Telemetry coverage

Rule body

name: Windows Increase in Group or Object Modification Activity
id: 4f9564dd-a204-4f22-b375-4dfca3a68731
version: 10
creation_date: '2024-07-01'
modification_date: '2026-05-13'
author: Dean Luxton
status: production
type: TTP
description: This analytic detects an increase in modifications to AD groups or objects. Frequent changes to AD groups or objects can indicate potential security risks, such as unauthorized access attempts, impairing defences or establishing persistence. By monitoring AD logs for unusual modification patterns, this detection helps identify suspicious behavior that could compromise the integrity and security of the AD environment.
data_source:
    - Windows Event Log Security 4663
search: |-
    `wineventlog_security` EventCode IN (4670,4727,4731,4734,4735,4764)
      | bucket span=5m _time
      | stats values(object) as object, dc(object) as objectCount, values(src_user_category) as src_user_category, values(dest) as dest, values(dest_category) as dest_category
        BY _time, src_user, signature,
           status
      | eventstats avg(objectCount) as comp_avg, stdev(objectCount) as comp_std
        BY src_user, signature
      | eval upperBound=(comp_avg+comp_std)
      | eval isOutlier=if(objectCount > 10 and (objectCount >= upperBound), 1, 0)
      | search isOutlier=1
      | `windows_increase_in_group_or_object_modification_activity_filter`
how_to_implement: Run this detection looking over a 7 day timeframe for best results.
known_false_positives: No false positives have been identified at this time.
references: []
finding:
    title: Spike in Group or Object Modifications performed by $src_user$
    entity:
        field: src_user
        type: user
        score: 50
analytic_story:
    - Sneaky Active Directory Persistence Tricks
asset_type: Endpoint
mitre_attack_id:
    - T1098
    - T1685
product:
    - Splunk Enterprise
    - Splunk Enterprise Security
    - Splunk Cloud
category: endpoint
security_domain: audit

Stages and Predicates

Stage 1: search

`wineventlog_security` EventCode IN (4670,4727,4731,4734,4735,4764)

Stage 2: bucket

| bucket span=5m _time

Stage 3: stats

| stats values(object) as object, dc(object) as objectCount, values(src_user_category) as src_user_category, values(dest) as dest, values(dest_category) as dest_category
    BY _time, src_user, signature,
       status

Stage 4: eventstats

| eventstats avg(objectCount) as comp_avg, stdev(objectCount) as comp_std
    BY src_user, signature

Stage 5: eval

| eval upperBound=(comp_avg+comp_std)

Stage 6: eval

| eval isOutlier=if(objectCount > 10 and (objectCount >= upperBound), 1, 0)
isOutlier =
ifobjectCount > 10 AND objectCount >= upperBound1
else0

Stage 7: search

| search isOutlier=1

Stage 8: search

| `windows_increase_in_group_or_object_modification_activity_filter`

Indicators

These rows show field, operator, and value matches.

FieldKindValuesSearch
EventCodein
  • 4670
  • 4727
  • 4731
  • 4734
  • 4735
  • 4764
field:"EventID" kind:in
isOutliereq
  • 1 corpus 33 (splunk 33)
field:"isOutlier" kind:eq value:"1"