Detection: Windows Get-AdComputer Unconstrained Delegation Discovery

Updated Date: 2024-09-30 ID: c8640777-469f-4638-ab44-c34a3233ffac Author: Mauricio Velazco, Splunk Type: TTP Product: Splunk Enterprise Security

Description

The following analytic detects the use of the Get-ADComputer cmdlet with parameters indicating a search for Windows endpoints with Kerberos Unconstrained Delegation. It leverages PowerShell Script Block Logging (EventCode=4104) to identify this specific activity. This behavior is significant as it may indicate an attempt by adversaries or Red Teams to gain situational awareness and perform Active Directory discovery. If confirmed malicious, this activity could allow attackers to identify high-value targets for further exploitation, potentially leading to privilege escalation or lateral movement within the network.

1`powershell` EventCode=4104 (ScriptBlockText = "*Get-ADComputer*" AND ScriptBlockText = "*TrustedForDelegation*") 
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_get_adcomputer_unconstrained_delegation_discovery_filter`

Data Source

Name Platform Sourcetype Source
Powershell Script Block Logging 4104 Windows icon 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_get_adcomputer_unconstrained_delegation_discovery_filter search *
windows_get_adcomputer_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-ADComputer 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: 5