Detection: Detect Prohibited Applications Spawning cmd exe

Description

The following analytic detects executions of cmd.exe spawned by processes that are commonly abused by attackers and do not typically launch cmd.exe. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on process GUID, process name, parent process, and command-line executions. This activity is significant because it may indicate an attempt to execute unauthorized commands or scripts, often a precursor to further malicious actions. If confirmed malicious, this behavior could lead to unauthorized code execution, privilege escalation, or persistence within the environment.

Search

1
2| tstats `security_content_summariesonly` count values(Processes.process) as process min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Processes where `process_cmd` by Processes.parent_process_name Processes.process_name Processes.original_file_name Processes.dest Processes.user
3| `drop_dm_object_name(Processes)` 
4| `security_content_ctime(firstTime)`
5| `security_content_ctime(lastTime)` 
6|search [`prohibited_apps_launching_cmd_macro`] 
7| `detect_prohibited_applications_spawning_cmd_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

There are circumstances where an application may legitimately execute and interact with the Windows command-line interface. Investigate and modify the lookup file, as appropriate.

Associated Analytic Story

• NOBELIUM Group

• Suspicious Command-Line Executions

• Suspicious MSHTA Activity

• Suspicious Zoom Child Processes

Risk Based Analytics (RBA)

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