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Description

This analytic is to detect a suspicious creation of .wav file in appdata folder. This behavior was seen in Remcos RAT malware where it put the audio recording in the appdata\audio folde as part of data collection. this recording can be send to its C2 server as part of its exfiltration to the compromised machine. creation of wav files in this folder path is not a ussual disk place used by user to save audio format file.

  • Type: TTP
  • Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
  • Datamodel: Endpoint
  • Last Updated: 2021-09-21
  • Author: Teoderick Contreras, Splunk
  • ID: 5be109e6-1ac5-11ec-b421-acde48001122

ATT&CK

ID Technique Tactic
T1113 Screen Capture Collection

| tstats `security_content_summariesonly` count FROM datamodel=Endpoint.Processes where Processes.process_name=*.exe Processes.process_path="*\\appdata\\Roaming\\*" by _time span=1h Processes.process_id Processes.process_name Processes.process Processes.dest 
| `drop_dm_object_name(Processes)` 
| join process_guid, _time [
| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime FROM datamodel=Endpoint.Filesystem where Filesystem.file_name IN ("*.wav") Filesystem.file_path = "*\\appdata\\Roaming\\*" by _time span=1h Filesystem.dest Filesystem.file_create_time Filesystem.file_name Filesystem.file_path 
| `drop_dm_object_name(Filesystem)` 
| fields file_name file_path process_name process_path process dest file_create_time _time ] 
| `suspicious_wav_file_in_appdata_folder_filter`

Associated Analytic Story

How To Implement

To successfully implement this search, you need to be ingesting logs with the process name, parent process, file_name, file_path and command-line executions from your endpoints. If you are using Sysmon, you must have at least version 6.0.4 of the Sysmon TA.

Required field

  • _time
  • dest
  • file_create_time
  • file_name
  • file_path
  • process_name
  • process_path
  • process

Kill Chain Phase

  • Exploitation

Known False Positives

unknown

RBA

Risk Score Impact Confidence Message
49.0 70 70 process $process_name$ creating image file $file_path$ in $dest$

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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