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Description

This analytic is to detect a suspicious dxdiag.exe process command-line execution. Dxdiag is used to collect the system info of the target host. This technique has been used by Remcos RATS, various actors, and other malware to collect information as part of the recon or collection phase of an attack. This behavior should rarely be seen in a corporate network, but this command line can be used by a network administrator to audit host machine specifications. Thus in some rare cases, this detection will contain false positives in its results. To triage further, analyze what commands were passed after it pipes out the result to a file for further processing.

  • Type: Hunting
  • Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
  • Datamodel: Endpoint
  • Last Updated: 2021-11-19
  • Author: Teoderick Contreras, Splunk
  • ID: f92d74f2-4921-11ec-b685-acde48001122

ATT&CK

ID Technique Tactic
T1592 Gather Victim Host Information Reconnaissance

| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Processes where `process_dxdiag` AND Processes.process = "* /t *" by Processes.dest Processes.user Processes.parent_process_name Processes.parent_process Processes.process_name Processes.process Processes.process_id Processes.parent_process_id 
| `drop_dm_object_name(Processes)` 
| `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)` 
| `system_info_gathering_using_dxdiag_application_filter`

Associated Analytic Story

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 and Filesystem node. In addition, confirm the latest CIM App 4.20 or higher is installed and the latest TA for the endpoint product.

Required field

  • _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

Kill Chain Phase

  • Reconnaissance

Known False Positives

This commandline can be used by a network administrator to audit host machine specifications. Thus, a filter is needed.

RBA

Risk Score Impact Confidence Message
25.0 50 50 dxdiag.exe process with commandline $process$ on $dest$

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

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