Detection: Create or delete windows shares using net exe

Description

The following analytic detects the creation or deletion of Windows shares using the net.exe command. It leverages Endpoint Detection and Response (EDR) data to identify processes involving net.exe with actions related to share management. This activity is significant because it may indicate an attacker attempting to manipulate network shares for malicious purposes, such as data exfiltration, malware distribution, or establishing persistence. If confirmed malicious, this activity could lead to unauthorized access to sensitive information, service disruption, or malware introduction. Immediate investigation is required to determine the intent and mitigate potential threats.

Search

1
2| tstats `security_content_summariesonly` count values(Processes.user) as user values(Processes.parent_process) as parent_process min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Processes where `process_net` by Processes.process Processes.process_name  Processes.parent_process_name Processes.original_file_name Processes.dest 
3| `drop_dm_object_name(Processes)` 
4| `security_content_ctime(firstTime)`
5| `security_content_ctime(lastTime)` 
6| search process=*share* 
7| `create_or_delete_windows_shares_using_net_exe_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

Administrators often leverage net.exe to create or delete network shares. You should verify that the activity was intentional and is legitimate.

Associated Analytic Story

• CISA AA22-277A

• DarkGate Malware

• Hidden Cobra Malware

• Prestige Ransomware

• Windows Post-Exploitation

Risk Based Analytics (RBA)

References

• https://attack.mitre.org/techniques/T1070/005/

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: 9