Detection: GetWmiObject Ds Computer with PowerShell

Description

The following analytic detects the execution of powershell.exe with command-line arguments that utilize the Get-WmiObject cmdlet to discover remote systems, specifically targeting the DS_Computer parameter. This detection leverages data from Endpoint Detection and Response (EDR) agents, focusing on process names and command-line executions. This activity is significant as it indicates potential reconnaissance efforts by adversaries to enumerate domain computers and gather situational awareness within Active Directory. If confirmed malicious, this behavior could allow attackers to map the network, identify critical systems, and plan further attacks, potentially leading to unauthorized access and data exfiltration.

Search

 1
 2| tstats `security_content_summariesonly`
 3  count min(_time) as firstTime
 4        max(_time) as lastTime
 5
 6from datamodel=Endpoint.Processes where
 7
 8(
 9    `process_powershell`
10    OR
11    `process_cmd`
12)
13AND
14Processes.process = "*Get-WmiObject*"
15Processes.process = "*namespace *"
16Processes.process = "*root\\directory\\ldap*"
17Processes.process = "*class *"
18Processes.process = "* ds_computer*"
19
20by Processes.action Processes.dest Processes.original_file_name
21   Processes.parent_process Processes.parent_process_exec
22   Processes.parent_process_guid Processes.parent_process_id
23   Processes.parent_process_name Processes.parent_process_path
24   Processes.process Processes.process_exec Processes.process_guid
25   Processes.process_hash Processes.process_id
26   Processes.process_integrity_level Processes.process_name
27   Processes.process_path Processes.user
28   Processes.user_id Processes.vendor_product
29
30
31| `drop_dm_object_name(Processes)`
32
33| `security_content_ctime(firstTime)`
34
35| `security_content_ctime(lastTime)`
36
37| `getwmiobject_ds_computer_with_powershell_filter`

Data Source

Name	Platform	Sourcetype	Source
CrowdStrike ProcessRollup2	Other	'crowdstrike:events:sensor'	'crowdstrike'
Sysmon EventID 1	Windows	'XmlWinEventLog'	'XmlWinEventLog:Microsoft-Windows-Sysmon/Operational'
Windows Event Log Security 4688	Windows	'XmlWinEventLog'	'XmlWinEventLog:Security'

Macros Used

Annotations

Default Configuration

This detection is configured by default in Splunk Enterprise Security to run with the following settings:

Implementation

The detection is based on data that originates from Endpoint Detection and Response (EDR) agents. These agents are designed to provide security-related telemetry from the endpoints where the agent is installed. To implement this search, you must ingest logs that contain the process GUID, process name, and parent process. Additionally, you must ingest complete command-line executions. These logs must be processed using the appropriate Splunk Technology Add-ons that are specific to the EDR product. The logs must also be mapped to the Processes node of the Endpoint data model. Use the Splunk Common Information Model (CIM) to normalize the field names and speed up the data modeling process.

Known False Positives

Administrators or power users may use this command for troubleshooting.

Associated Analytic Story

• Active Directory Discovery

Risk Based Analytics (RBA)

Risk Message:

Remote system discovery enumeration using WMI via the command $process$ on $dest$ by $user$

References

• https://attack.mitre.org/techniques/T1018/

Detection Testing

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: 8