Detection: Processes launching netsh

Description

The following analytic identifies processes launching netsh.exe, a command-line utility used to modify network configurations. It detects this activity by analyzing data from Endpoint Detection and Response (EDR) agents, focusing on process GUIDs, names, parent processes, and command-line executions. This behavior is significant because netsh.exe can be exploited to execute malicious helper DLLs, serving as a persistence mechanism. If confirmed malicious, an attacker could gain persistent access, modify network settings, and potentially escalate privileges, posing a severe threat to the network's integrity and security.

Search

1
2| tstats `security_content_summariesonly` count values(Processes.process) AS Processes.process min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Processes where `process_netsh` by Processes.parent_process_name Processes.parent_process Processes.original_file_name Processes.process_name Processes.user Processes.dest 
3|`drop_dm_object_name("Processes")` 
4|`security_content_ctime(firstTime)` 
5|`security_content_ctime(lastTime)` 
6|`processes_launching_netsh_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

Some VPN applications are known to launch netsh.exe. Outside of these instances, it is unusual for an executable to launch netsh.exe and run commands.

Associated Analytic Story

• Azorult

• DHS Report TA18-074A

• Disabling Security Tools

• Netsh Abuse

• ShrinkLocker

• Snake Keylogger

• Volt Typhoon

Risk Based Analytics (RBA)

References

• https://www.microsoft.com/en-us/security/blog/2023/05/24/volt-typhoon-targets-us-critical-infrastructure-with-living-off-the-land-techniques/

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: 6