Detection: Remote Process Instantiation via WMI and PowerShell Script Block

Updated Date: 2024-05-14 ID: 2a048c14-4634-11ec-a618-3e22fbd008af Author: Mauricio Velazco, Splunk Type: TTP Product: Splunk Enterprise Security

Description

The following analytic detects the execution of the Invoke-WmiMethod commandlet with parameters used to start a process on a remote endpoint via WMI, leveraging PowerShell Script Block Logging (EventCode=4104). This method identifies specific script block text patterns associated with remote process instantiation. This activity is significant as it may indicate lateral movement or remote code execution attempts by adversaries. If confirmed malicious, this could allow attackers to execute arbitrary code on remote systems, potentially leading to further compromise and persistence within the network.

Search

1`powershell` EventCode=4104 ScriptBlockText="*Invoke-WmiMethod*" AND (ScriptBlockText="*-CN*" OR ScriptBlockText="*-ComputerName*") AND ScriptBlockText="*-Class Win32_Process*" AND ScriptBlockText="*-Name create*" 
2| stats count min(_time) as firstTime max(_time) as lastTime by EventCode ScriptBlockText Computer UserID
3|  `security_content_ctime(firstTime)` 
4| `security_content_ctime(lastTime)` 
5| `remote_process_instantiation_via_wmi_and_powershell_script_block_filter`

Data Source

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

Macros Used

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

remote_process_instantiation_via_wmi_and_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
T1047	Windows Management Instrumentation	Execution

KillChainPhase.INSTALLATION

NistCategory.DE_CM

Cis18Value.CIS_10

APT29

APT32

APT41

Blue Mockingbird

Chimera

Cinnamon Tempest

Deep Panda

Earth Lusca

FIN13

FIN6

FIN7

FIN8

GALLIUM

Gamaredon Group

Indrik Spider

Lazarus Group

Leviathan

Magic Hound

MuddyWater

Mustang Panda

Naikon

OilRig

Sandworm Team

Stealth Falcon

TA2541

Threat Group-3390

ToddyCat

Volt Typhoon

Windshift

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

To successfully implement this analytic, you will need to enable PowerShell Script Block Logging on some or all endpoints. Additional setup instructions can be found https://docs.splunk.com/Documentation/UBA/5.0.4.1/GetDataIn/AddPowerShell#Configure_module_logging_for_PowerShell.

Known False Positives

Administrators may leverage WWMI and powershell.exe to start a process on remote systems, but this activity is usually limited to a small set of hosts or users.

Associated Analytic Story

Active Directory Lateral Movement

Risk Based Analytics (RBA)

Risk Message	Risk Score	Impact	Confidence
A process was started on a remote endpoint from $Computer$ by abusing WMI using PowerShell.exe	63	90	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: 3