Detection: Domain Group Discovery with Adsisearcher

Updated Date: 2024-09-30 ID: 089c862f-5f83-49b5-b1c8-7e4ff66560c7 Author: Mauricio Velazco, Splunk Type: TTP Product: Splunk Enterprise Security

Description

The following analytic detects the use of the [Adsisearcher] type accelerator in PowerShell to query Active Directory for domain groups. It leverages PowerShell Script Block Logging (EventCode=4104) to identify specific script blocks containing [adsisearcher] and group-related queries. This activity is significant as it may indicate an attempt by adversaries or Red Teams to enumerate domain groups for situational awareness and Active Directory discovery. If confirmed malicious, this behavior could lead to further reconnaissance, privilege escalation, or lateral movement within the network.

Search

1`powershell` (ScriptBlockText = "*[adsisearcher]*" AND ScriptBlockText = "*(objectcategory=group)*" AND ScriptBlockText = "*findAll()*") 
2| stats count min(_time) as firstTime max(_time) as lastTime by EventCode ScriptBlockText Computer UserID 
3| rename Computer as dest 
4|rename UserID as user 
5| `security_content_ctime(firstTime)` 
6| `domain_group_discovery_with_adsisearcher_filter`

Data Source

Name	Platform	Sourcetype	Source
Powershell Script Block Logging 4104	Windows	`'xmlwineventlog'`	`'XmlWinEventLog:Microsoft-Windows-PowerShell/Operational'`

Macros Used

Name	Value
powershell	`(source=WinEventLog:Microsoft-Windows-PowerShell/Operational OR source="XmlWinEventLog:Microsoft-Windows-PowerShell/Operational")`
domain_group_discovery_with_adsisearcher_filter	`search *`

domain_group_discovery_with_adsisearcher_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
T1069	Permission Groups Discovery	Discovery
T1069.002	Domain Groups	Discovery

KillChainPhase.EXPLOITAITON

NistCategory.DE_CM

Cis18Value.CIS_10

APT3

APT41

FIN13

TA505

Volt Typhoon

Dragonfly

FIN7

INC Ransom

Inception

Ke3chang

LAPSUS$

OilRig

ToddyCat

Turla

Volt Typhoon

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 analytic, you will need to enable PowerShell Script Block Logging on some or all endpoints. Additional setup here https://docs.splunk.com/Documentation/UBA/5.0.4.1/GetDataIn/AddPowerShell#Configure_module_logging_for_PowerShell.

Known False Positives

Administrators or power users may use Adsisearcher for troubleshooting.

Associated Analytic Story

Active Directory Discovery

Risk Based Analytics (RBA)

Risk Message	Risk Score	Impact	Confidence
Domain group discovery enumeration using PowerShell on $dest$ by $user$	18	30	60

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:Microsoft-Windows-PowerShell/Operational`	`XmlWinEventLog`
Integration	✅ Passing	Dataset	`XmlWinEventLog:Microsoft-Windows-PowerShell/Operational`	`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: 4