Detection: Windows AD Privileged Object Access Activity

Updated Date: 2024-05-18 ID: dc2f58bc-8cd2-4e51-962a-694b963acde0 Author: Steven Dick Type: TTP Product: Splunk Enterprise Security

Description

The following analytic detects access attempts to privileged Active Directory objects, such as Domain Admins or Enterprise Admins. It leverages Windows Security Event Code 4662 to identify when these sensitive objects are accessed. This activity is significant because such objects should rarely be accessed by normal users or processes, and unauthorized access attempts may indicate attacker enumeration or lateral movement within the domain. If confirmed malicious, this activity could allow attackers to escalate privileges, persist in the environment, or gain control over critical domain resources.

Search

1`wineventlog_security` EventCode=4662 ObjectName IN ( "CN=Account Operators,*", "CN=Administrators,*", "CN=Backup Operators,*", "CN=Cert Publishers,*", "CN=Certificate Service DCOM Access,*", "CN=Domain Admins,*", "CN=Domain Controllers,*", "CN=Enterprise Admins,*", "CN=Enterprise Read-only Domain Controllers,*", "CN=Group Policy Creator Owners,*", "CN=Incoming Forest Trust Builders,*", "CN=Microsoft Exchange Servers,*", "CN=Network Configuration Operators,*", "CN=Power Users,*", "CN=Print Operators,*", "CN=Read-only Domain Controllers,*", "CN=Replicators,*", "CN=Schema Admins,*", "CN=Server Operators,*", "CN=Exchange Trusted Subsystem,*", "CN=Exchange Windows Permission,*", "CN=Organization Management,*") 
2| rex field=ObjectName "CN\=(?<object_name>[^,]+)" 
3| stats values(Computer) as dest, values(object_name) as object_name, dc(ObjectName) as object_count, min(_time) as firstTime, max(_time) as lastTime, count by SubjectUserName 
4| rename SubjectUserName as user 
5| `security_content_ctime(firstTime)` 
6| `security_content_ctime(lastTime)` 
7| `windows_ad_privileged_object_access_activity_filter`

Data Source

Name	Platform	Sourcetype	Source	Supported App
Windows Event Log Security 4662	Windows	`'xmlwineventlog'`	`'XmlWinEventLog:Security'`	N/A

Macros Used

Name	Value
security_content_ctime	`convert timeformat="%Y-%m-%dT%H:%M:%S" ctime($field$)`
windows_ad_privileged_object_access_activity_filter	`search *`

windows_ad_privileged_object_access_activity_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
T1087	Account Discovery	Discovery
T1087.002	Domain Account	Discovery

KillChainPhase.EXPLOITAITON

NistCategory.DE_CM

Cis18Value.CIS_10

FIN13

APT41

BRONZE BUTLER

Chimera

Dragonfly

FIN13

FIN6

Fox Kitten

Ke3chang

LAPSUS$

MuddyWater

OilRig

Poseidon Group

Sandworm Team

Scattered Spider

ToddyCat

Turla

Volt Typhoon

Wizard Spider

menuPass

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

Enable Audit Directory Service Access via GPO and collect event code 4662. The required SACLs need to be created for the relevant objects. Be aware Splunk filters this event by default on the Windows TA.

Known False Positives

Service accounts or applications that routinely query Active Directory for information.

Associated Analytic Story

Risk Based Analytics (RBA)

Risk Message	Risk Score	Impact	Confidence
The account $user$ accessed $object_count$ privileged AD object(s).	40	80	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	`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: 2