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Description

The following analytic identifies command-line arguments where cmd.exe /c is used to execute a program. cmd /c is used to run commands in MS-DOS and terminate after command or process completion. This technique is commonly seen in adversaries and malware to execute batch command using different shell like PowerShell or different process other than cmd.exe. This is a good hunting query for suspicious command-line made by a script or relative process execute it.

  • Type: Hunting
  • Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
  • Datamodel: Endpoint
  • Last Updated: 2022-01-18
  • Author: Teoderick Contreras, Bhavin Patel, Splunk
  • ID: 54a6ed00-3256-11ec-b031-acde48001122

Annotations

ATT&CK

ATT&CK

ID Technique Tactic
T1059.003 Windows Command Shell Execution
T1059 Command and Scripting Interpreter Execution
Kill Chain Phase
  • Exploitation
NIST
CIS20
CVE
1
2
3
4
5
6
| tstats `security_content_summariesonly` min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Processes where `process_cmd` AND Processes.process="* /c *" by Processes.dest Processes.user Processes.parent_process Processes.process_name Processes.original_file_name Processes.process Processes.process_id Processes.parent_process_id 
| `drop_dm_object_name(Processes)` 
| `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)` 
| `cmd_carry_out_string_command_parameter_filter`

Macros

The SPL above uses the following Macros:

:information_source: cmd_carry_out_string_command_parameter_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.parent_process_name
  • Processes.parent_process
  • Processes.process_name
  • Processes.process_id
  • Processes.process
  • Processes.dest
  • Processes.user
  • Processes.process_id
  • Processes.parent_process_id

How To Implement

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

False positives may be high based on legitimate scripted code in any environment. Filter as needed.

Associated Analytic Story

RBA

Risk Score Impact Confidence Message
30.0 60 50 An instance of $parent_process_name$ spawning $process_name$ was identified on endpoint $dest$ by user $user$ attempting spawn a new process.

: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: 3