Capture Audio

Adversaries may capture audio to collect information on a user of a mobile device using standard operating system APIs. Adversaries may target audio information such as user conversations, surroundings, phone calls, or other sensitive information.

Android and iOS, by default, requires that an application request access to microphone devices from the user. In Android, applications must hold the android.permission.RECORD_AUDIO permission to access the microphone and the android.permission.CAPTURE_AUDIO_OUTPUT permission to access audio output such as speakers. Android does not allow third-party applications to hold android.permission.CAPTURE_AUDIO_OUTPUT, so audio output can only be obtained by privileged applications (distributed by Google or the device vendor) or after a successful privilege escalation attack. In iOS, applications must include the NSMicrophoneUsageDescription key in their Info.plist file.

ID: T1429
Sub-techniques:  No sub-techniques
Tactic Type: Post-Adversary Device Access
Tactic: Collection
Platforms: Android, iOS
MTC ID: APP-19
Version: 2.0
Created: 25 October 2017
Last Modified: 20 September 2019

Procedure Examples

Name Description
AndroRAT

AndroRAT gathers audio from the microphone.[5]

Dendroid

Dendroid can record audio using the device microphone.[4]

DroidJack

DroidJack is capable of recording device phone calls.[14]

Exodus

Exodus Two can record audio from the compromised device's microphone and can record call audio in 3GP format.[16]

FinFisher

FinFisher uses the device microphone to record phone conversations.[15]

FlexiSpy

FlexiSpy can record both incoming and outgoing phone calls, as well as microphone audio.[2]

GolfSpy

GolfSpy can record audio and phone calls.[20]

Monokle

Monokle can record audio from the device's microphone and can record phone calls, specifying the output audio quality.[17]

Pallas

Pallas captures audio from the device microphone.[15]

Pegasus for Android

Pegasus for Android has the ability to record device audio.[7]

Pegasus for iOS

Pegasus for iOS has the ability to record audio.[12]

RCSAndroid

RCSAndroid can record audio using the device microphone.[9]

RedDrop

RedDrop captures live recordings of the device's surroundings.[13]

Skygofree

Skygofree can record audio via the microphone when an infected device is in a specified location.[11]

SpyDealer

SpyDealer can record phone calls and surrounding audio.[10]

SpyNote RAT

SpyNote RAT can activate the victim's microphone.[6]

Stealth Mango

Stealth Mango can record audio using the device microphone.[3]

Tangelo

Tangelo contains functionality to record calls as well as the victim device's environment.[3]

ViceLeaker

ViceLeaker can record audio from the device’s microphone and can record phone calls together with the caller ID.[18][19]

XLoader

XLoader covertly records phone calls.[8]

Mitigations

Mitigation Description
Application Vetting

Applications using the android permission android.permission.RECORD_AUDIO or iOS applications using RequestRecordPermission could be more closely scrutinized and monitored. If android.permission.CAPTURE_AUDIO_OUTPUT is found in a third-party application, it should be heavily scrutinized.

Use Recent OS Version

Android 9 and above restricts access to microphone, camera, and other sensors from background applications.[1]

Detection

On both Android (6.0 and up) and iOS, the user can view which applications have permission to use the microphone through the device settings screen, and the user can choose to revoke the permissions.

References