T1123 - Audio Capture

Description from ATT&CK (opens in a new tab)

An adversary can leverage a computer's peripheral devices (e.g., microphones and webcams) or applications (e.g., voice and video call services) to capture audio recordings for the purpose of listening into sensitive conversations to gather information.(Citation: ESET Attor Oct 2019)

Malware or scripts may be used to interact with the devices through an available API provided by the operating system or an application to capture audio. Audio files may be written to disk and exfiltrated later.

Atomic Tests

• Atomic Test #1 - using device audio capture commandlet

• Atomic Test #2 - Registry artefact when application use microphone

• Atomic Test #3 - using Quicktime Player

Atomic Test #1 - using device audio capture commandlet

AudioDeviceCmdlets (opens in a new tab)

Supported Platforms: Windows

auto_generated_guid: 9c3ad250-b185-4444-b5a9-d69218a10c95

Attack Commands: Run with powershell!

powershell.exe -Command WindowsAudioDevice-Powershell-Cmdlet

Atomic Test #2 - Registry artefact when application use microphone

can-you-track-processes-accessing-the-camera-and-microphone (opens in a new tab)

Supported Platforms: Windows

auto_generated_guid: 7a21cce2-6ada-4f7c-afd9-e1e9c481e44a

Attack Commands: Run with command_prompt!

reg add HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\CapabilityAccessManager\ConsentStore\microphone\NonPackaged\C:#Windows#Temp#atomic.exe /v LastUsedTimeStart /t REG_BINARY /d a273b6f07104d601 /f
reg add HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\CapabilityAccessManager\ConsentStore\microphone\NonPackaged\C:#Windows#Temp#atomic.exe /v LastUsedTimeStop /t REG_BINARY /d 96ef514b7204d601 /f

Cleanup Commands:

reg DELETE HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\CapabilityAccessManager\ConsentStore\microphone\NonPackaged\C:#Windows#Temp#atomic.exe /f

Atomic Test #3 - using Quicktime Player

Use AppleScript to get Quicktime Player to record an audio file from the default microphone.

Should create a non-empty m4a file with sound from the microphone.

• requires Automation permissions but no additional microphone permissions
• saves file in /tmp by default. Other locations likely to require more permissions.

Supported Platforms: macOS

auto_generated_guid: c7a0bb71-70ce-4a53-b115-881f241b795b

Inputs:

Attack Commands: Run with sh!

sh #{filename} #{audiofile} #{duration}

Cleanup Commands:

if test -w #{audiofile}; then
  rm #{audiofile}
fi