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Description

This search looks for executions of cmd.exe spawned by a process that is often abused by attackers and that does not typically launch cmd.exe.

  • Type: Hunting
  • Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
  • Datamodel: Endpoint
  • Last Updated: 2020-11-10
  • Author: Bhavin Patel, Splunk
  • ID: dcfd6b40-42f9-469d-a433-2e53f7486664

Annotations

ATT&CK

ATT&CK

ID Technique Tactic
T1059 Command and Scripting Interpreter Execution
T1059.003 Windows Command Shell Execution
Kill Chain Phase
  • Installation
NIST
  • DE.AE
CIS20
  • CIS 10
CVE 


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| 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
| `drop_dm_object_name(Processes)` 
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)` 
|search [`prohibited_apps_launching_cmd`] 
| `detect_prohibited_applications_spawning_cmd_exe_filter`

Macros

The SPL above uses the following Macros:

:information_source: detect_prohibited_applications_spawning_cmd_exe_filter is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Required fields

List of fields required to use this analytic.

  • _time
  • Processes.dest
  • Processes.user
  • Processes.parent_process_name
  • Processes.parent_process
  • Processes.original_file_name
  • Processes.process_name
  • Processes.process
  • Processes.process_id
  • Processes.parent_process_path
  • Processes.process_path
  • Processes.parent_process_id

How To Implement

You must be ingesting data that records process activity from your hosts and populates the Endpoint data model with the resultant dataset. This search includes a lookup file, prohibited_apps_launching_cmd.csv, that contains a list of processes that should not be spawning cmd.exe. You can modify this lookup to better suit your environment. To successfully implement this search you need to be ingesting information on process that include the name of the process responsible for the changes from your endpoints into the Endpoint datamodel in the Processes node. In addition, confirm the latest CIM App 4.20 or higher is installed and the latest TA for the endpoint product.

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

RBA

Risk Score Impact Confidence Message
80.0 80 100 An instance of $parent_process_name$ spawning $process_name$ was identified on endpoint $dest$ by user $user$ running prohibited applications.

:information_source: The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.

Reference

Test Dataset

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 | version: 6