Detection: Net Localgroup Discovery

Description

The following analytic detects the execution of the net localgroup command, which is used to enumerate local group memberships on a system. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on process execution logs that include command-line details. This activity is significant because it can indicate an attacker is gathering information about local group memberships, potentially to identify privileged accounts. If confirmed malicious, this behavior could lead to further privilege escalation or lateral movement within the network.

Search

1
2| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Processes where Processes.process_name=net.exe OR Processes.process_name=net1.exe (Processes.process="*localgroup*") by Processes.dest Processes.user Processes.parent_process_name Processes.process_name Processes.process Processes.original_file_name Processes.process_id Processes.parent_process_id 
3| `drop_dm_object_name(Processes)` 
4| `security_content_ctime(firstTime)`
5| `security_content_ctime(lastTime)` 
6| `net_localgroup_discovery_filter`

Data Source

Name	Platform	Sourcetype	Source
CrowdStrike ProcessRollup2	N/A	'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

False positives may be present. Tune as needed.

Associated Analytic Story

• Active Directory Discovery

• Azorult

• Graceful Wipe Out Attack

• IcedID

• Prestige Ransomware

• Rhysida Ransomware

• Volt Typhoon

• Windows Discovery Techniques

• Windows Post-Exploitation

Risk Based Analytics (RBA)

References

• https://attack.mitre.org/techniques/T1069/001/

• https://github.com/redcanaryco/atomic-red-team/blob/master/atomics/T1069.001/T1069.001.md

• https://media.defense.gov/2023/May/24/2003229517/-1/-1/0/CSA_Living_off_the_Land.PDF

• https://thedfirreport.com/2023/05/22/icedid-macro-ends-in-nokoyawa-ransomware/

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: 3