Detection: Windows FFmpeg Audio and Video Device Discovery

Description

This analytic detects the use of FFmpeg (ffmpeg.exe) to enumerate connected audio and video devices on a Windows endpoint. Adversaries and stealers such as SalatStealer abuse FFmpeg's DirectShow (dshow) input interface by invoking it with the -list_devices true and -hide_banner flags from a temporary directory, allowing them to silently discover available webcams, microphones, and capture cards without triggering obvious user-facing activity. Device discovery of this kind maps to MITRE ATT&CK T1125 (Video Capture), where threat actors profile the system's multimedia capabilities as a precursor to covert audio or video surveillance. The combination of an unusual process path (temp), the dshow input filter, and the device-listing arguments is a strong indicator of malicious reconnaissance rather than legitimate administrative use.

Search

 1
 2| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime FROM datamodel=Endpoint.Processes
 3  WHERE (
 4          (
 5            Processes.process_name = ffmpeg.exe OR
 6            Processes.original_file_name = ffmpeg.exe
 7           ) AND
 8
 9          Processes.process_path IN ("*\\temp\\*") AND
10          Processes.process = "*-list_devices*" AND
11          Processes.process = "*-hide_banner*" AND
12          Processes.process = "* dshow *"
13        )
14  BY Processes.action Processes.dest Processes.original_file_name
15     Processes.parent_process Processes.parent_process_exec Processes.parent_process_guid
16     Processes.parent_process_id Processes.parent_process_name Processes.parent_process_path
17     Processes.process Processes.process_exec Processes.process_guid
18     Processes.process_hash Processes.process_id Processes.process_integrity_level
19     Processes.process_name Processes.process_path Processes.user
20     Processes.user_id Processes.vendor_product
21
22| `drop_dm_object_name(Processes)`
23
24| `security_content_ctime(firstTime)`
25
26| `security_content_ctime(lastTime)`
27
28| `windows_ffmpeg_audio_and_video_device_discovery_filter`

Data Source

Name	Platform	Sourcetype	Source
CrowdStrike ProcessRollup2	Other	'crowdstrike:events:sensor'	'crowdstrike'
Sysmon EventID 1	Windows	'XmlWinEventLog'	'XmlWinEventLog:Microsoft-Windows-Sysmon/Operational'
Windows Event Log Security 4688	Windows	'XmlWinEventLog'	'XmlWinEventLog:Security'

Macros Used

Annotations

Default Configuration

This detection is configured by default in Splunk Enterprise Security to run with the following settings:

Implementation

The detection is based on data that originates from Endpoint Detection and Response (EDR) agents. These agents are designed to provide security-related telemetry from the endpoints where the agent is installed. To implement this search, you must ingest logs that contain the process GUID, process name, and parent process. Additionally, you must ingest complete command-line executions. These logs must be processed using the appropriate Splunk Technology Add-ons that are specific to the EDR product. The logs must also be mapped to the Processes node of the Endpoint data model. Use the Splunk Common Information Model (CIM) to normalize the field names and speed up the data modeling process.

Known False Positives

Administrators or administrative scripts may use this application. Filter as needed.

Associated Analytic Story

• Salat Stealer

Intermediate Findings

Threat Objects

References

• https://www.broadcom.com/support/security-center/protection-bulletin/uac-0252-activity-delivering-shadowsniff-and-salatstealer-malware

• https://bazaar.abuse.ch/browse/tag/SalatStealer/

Detection Testing

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: GitHub | Version: 1