Try in Splunk Security Cloud

Description

DynamicWrapperX is an ActiveX component that can be used in a script to call Windows API functions, but it requires the dynwrapx.dll to be installed and registered. With that, a binary writing dynwrapx.dll to disk and registering it into the registry is highly suspect. Why is it needed? In most malicious instances, it will be written to disk at a non-standard location. During triage, review parallel processes and pivot on the process_guid. Review the registry for any suspicious modifications meant to load dynwrapx.dll. Identify any suspicious module loads of dynwrapx.dll. This will identify the process that will invoke vbs/wscript/cscript.

  • Type: Hunting
  • Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
  • Datamodel: Endpoint
  • Last Updated: 2021-10-05
  • Author: Michael Haag, Splunk
  • ID: b0a078e4-2601-11ec-9aec-acde48001122

ATT&CK

ID Technique Tactic
T1059 Command and Scripting Interpreter Execution
T1559.001 Component Object Model Execution

| tstats `security_content_summariesonly` count FROM datamodel=Endpoint.Processes by _time Processes.process_id Processes.process_name Processes.dest Processes.process_guid Processes.user 
| `drop_dm_object_name(Processes)` 
| join process_guid [
| tstats `security_content_summariesonly` count FROM datamodel=Endpoint.Filesystem where Filesystem.file_name="dynwrapx.dll" by _time Filesystem.dest Filesystem.file_create_time Filesystem.file_name Filesystem.file_path Filesystem.process_guid Filesystem.user 
| `drop_dm_object_name(Filesystem)` 
| fields _time process_guid file_path file_name file_create_time user dest process_name] 
| stats count min(_time) as firstTime max(_time) as lastTime by dest process_name process_guid file_name file_path file_create_time user 
| `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)` 
| `process_writing_dynamicwrapperx_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
  • dest
  • process_name
  • process_guid
  • file_name
  • file_path
  • file_create_time user

Kill Chain Phase

  • Exploitation

Known False Positives

False positives should be limited, however it is possible to filter by Processes.process_name and specific processes (ex. wscript.exe). Filter as needed. This may need modification based on EDR telemetry and how it brings in registry data. For example, removal of (Default).

RBA

Risk Score Impact Confidence Message
80.0 80 100 An instance of $process_name$ was identified on endpoint $dest$ downloading the DynamicWrapperX dll.

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: 1