Detection: Get-DomainTrust with PowerShell Script Block

Updated Date: 2024-09-30 ID: 89275e7e-0548-11ec-bf75-acde48001122 Author: Michael Haag, Splunk Type: TTP Product: Splunk Enterprise Security

Description

The following analytic detects the execution of the Get-DomainTrust command from PowerView using PowerShell Script Block Logging (EventCode=4104). This method captures the full command sent to PowerShell, allowing for detailed inspection. Identifying this activity is significant because it may indicate an attempt to gather domain trust information, which is often a precursor to lateral movement or privilege escalation. If confirmed malicious, this activity could enable an attacker to map trust relationships within the domain, potentially leading to further exploitation and compromise of additional systems.

Search

1`powershell` EventCode=4104 ScriptBlockText = "*get-domaintrust*" 
2| stats count min(_time) as firstTime max(_time) as lastTime by Opcode Computer UserID EventCode ScriptBlockText 
3| rename Computer as dest 
4| rename UserID as user 
5| `security_content_ctime(firstTime)` 
6| `security_content_ctime(lastTime)` 
7| `get_domaintrust_with_powershell_script_block_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")`
get_domaintrust_with_powershell_script_block_filter	`search *`

get_domaintrust_with_powershell_script_block_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
T1482	Domain Trust Discovery	Discovery

KillChainPhase.EXPLOITAITON

NistCategory.DE_CM

Cis18Value.CIS_10

Akira

Chimera

Earth Lusca

FIN8

Magic Hound

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

It is possible certain system management frameworks utilize this command to gather trust information.

Associated Analytic Story

Active Directory Discovery

Risk Based Analytics (RBA)

Risk Message	Risk Score	Impact	Confidence
Suspicious PowerShell Get-DomainTrust was identified on endpoint $dest$ by user $user$.	12	30	40

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