Detection: Windows PowerView Unconstrained Delegation Discovery

Updated Date: 2024-09-30 ID: fbf9e47f-e531-4fea-942d-5c95af7ed4d6 Author: Mauricio Velazco, Splunk Type: TTP Product: Splunk Enterprise Security

Description

The following analytic detects the use of PowerView commandlets to discover Windows endpoints with Kerberos Unconstrained Delegation. It leverages PowerShell Script Block Logging (EventCode=4104) to identify specific commands like Get-DomainComputer or Get-NetComputer with the -Unconstrained parameter. This activity is significant as it indicates potential reconnaissance efforts by adversaries or Red Teams to map out privileged delegation settings in Active Directory. If confirmed malicious, this could allow attackers to identify high-value targets for further exploitation, potentially leading to privilege escalation or lateral movement within the network.

Search

1`powershell` EventCode=4104 (ScriptBlockText = "*Get-DomainComputer*" OR ScriptBlockText = "*Get-NetComputer*") AND (ScriptBlockText = "*-Unconstrained*") 
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| `security_content_ctime(lastTime)` 
7| `windows_powerview_unconstrained_delegation_discovery_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")`
windows_powerview_unconstrained_delegation_discovery_filter	`search *`

windows_powerview_unconstrained_delegation_discovery_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
T1018	Remote System Discovery	Discovery

KillChainPhase.EXPLOITAITON

NistCategory.DE_CM

Cis18Value.CIS_10

APT3

APT32

APT39

APT41

Agrius

Akira

BRONZE BUTLER

Chimera

Deep Panda

Dragonfly

Earth Lusca

Ember Bear

FIN5

FIN6

FIN8

Fox Kitten

GALLIUM

HAFNIUM

HEXANE

Indrik Spider

Ke3chang

Leafminer

Magic Hound

Naikon

Play

Rocke

Sandworm Team

Scattered Spider

Silence

Threat Group-3390

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

The following analytic requires PowerShell operational logs to be imported. Modify the powershell macro as needed to match the sourcetype or add index. This analytic is specific to 4104, or PowerShell Script Block Logging.

Known False Positives

Administrators or power users may leverage PowerView for system management or troubleshooting.

Associated Analytic Story

Risk Based Analytics (RBA)

Risk Message	Risk Score	Impact	Confidence
Suspicious PowerShell Get-DomainComputer was identified on endpoint $dest$	35	50	70

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