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Audio Capture

Adversaries may capture audio to collect information by leveraging standard operating system APIs of a mobile device. Examples of audio information adversaries may target include user conversations, surroundings, phone calls, or other sensitive information.

Android and iOS, by default, require that applications request device microphone access from the user.

On Android devices, applications must hold the RECORD_AUDIO permission to access the microphone or the CAPTURE_AUDIO_OUTPUT permission to access audio output. Because Android does not allow third-party applications to hold the CAPTURE_AUDIO_OUTPUT permission by default, only privileged applications, such as those distributed by Google or the device vendor, can access audio output.[1] However, adversaries may be able to gain this access after successfully elevating their privileges. With the CAPTURE_AUDIO_OUTPUT permission, adversaries may pass the MediaRecorder.AudioSource.VOICE_CALL constant to MediaRecorder.setAudioOutput, allowing capture of both voice call uplink and downlink.[2]

On iOS devices, applications must include the NSMicrophoneUsageDescription key in their Info.plist file to access the microphone.[3]

ID: T1429
Sub-techniques:  No sub-techniques
Tactic Type: Post-Adversary Device Access
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Tactic: Collection
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Platforms: Android, iOS
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MTC ID: APP-19
Version: 3.1
Created: 25 October 2017
Last Modified: 16 March 2023
Version Permalink

Procedure Examples

ID Name Description
S1061 AbstractEmu

AbstractEmu can grant itself microphone permissions.[4]
S1095 AhRat

AhRat can record audio using a device’s microphone.[5]
S0292 AndroRAT

AndroRAT gathers audio from the microphone.[6][7]

S0422 Anubis

Anubis can record phone calls and audio.[8]
S1079 BOULDSPY

BOULDSPY can access a device’s microphone to record audio, as well as cell and VoIP application calls.[9]
S0655 BusyGasper

BusyGasper can record audio.[10]
C0033 C0033

During C0033, PROMETHIUM used StrongPity to record phone calls.[11]

S0529 CarbonSteal

CarbonSteal can remotely capture device audio.[12]
S0425 Corona Updates

Corona Updates can record MP4 files and monitor calls.[13]
S0301 Dendroid

Dendroid can record audio and outgoing calls.[14]
S0505 Desert Scorpion

Desert Scorpion can record audio from phone calls and the device microphone.[15]
S0550 DoubleAgent

DoubleAgent has captured audio and can record phone calls.[12]
S0320 DroidJack

DroidJack is capable of recording device phone calls.[16]
S1092 Escobar

Escobar can record audio from the device’s microphone.[17]
S0507 eSurv

eSurv can record audio.[18]
S0405 Exodus

Exodus Two can record audio from the compromised device's microphone and can record call audio in 3GP format.[19]

S1080 Fakecalls

Fakecalls can turn on a device’s microphone to capture audio.[20]
S0182 FinFisher

FinFisher uses the device microphone to record phone conversations.[21]
S0408 FlexiSpy

FlexiSpy can record both incoming and outgoing phone calls, as well as microphone audio.[22]
S0577 FrozenCell

FrozenCell has recorded calls.[23]
S0535 Golden Cup

Golden Cup can record audio from the microphone and phone calls.[24]

S0551 GoldenEagle

GoldenEagle has recorded calls and environment audio in .amr format.[12]
S0421 GolfSpy

GolfSpy can record audio and phone calls.[25]
S0544 HenBox

HenBox can access the device’s microphone.[26]
S1128 HilalRAT

HilalRAT can activate a device’s microphone.[27]
S1077 Hornbill

Hornbill can record environmental and call audio.[28]
S0407 Monokle

Monokle can record audio from the device's microphone and can record phone calls, specifying the output audio quality.[29]
S0399 Pallas

Pallas captures audio from the device microphone.[21]
S0316 Pegasus for Android

Pegasus for Android has the ability to record device audio.[30]
S0289 Pegasus for iOS

Pegasus for iOS has the ability to record audio.[31]
S1126 Phenakite

Phenakite can record phone calls.[32]
S0295 RCSAndroid

RCSAndroid can record audio using the device microphone.[33]
S0326 RedDrop

RedDrop captures live recordings of the device's surroundings.[34]
S0327 Skygofree

Skygofree can record audio via the microphone when an infected device is in a specified location.[35]
S0324 SpyDealer

SpyDealer can record phone calls and surrounding audio.[36]
S0305 SpyNote RAT

SpyNote RAT can activate the victim's microphone.[37]
S0328 Stealth Mango

Stealth Mango can record audio using the device microphone.[38]
S1082 Sunbird

Sunbird can record environmental and call audio.[28]
S0329 Tangelo

Tangelo contains functionality to record calls as well as the victim device's environment.[38]
S1069 TangleBot

TangleBot can record audio using the device microphone.[39]
S0558 Tiktok Pro

Tiktok Pro can capture audio from the device’s microphone and can record phone calls.[40]
S0418 ViceLeaker

ViceLeaker can record audio from the device’s microphone and can record phone calls together with the caller ID.[41][42]
S0506 ViperRAT

ViperRAT can collect and record audio content.[43]
G0112 Windshift

Windshift has included phone call and audio recording capabilities in the malicious apps deployed as part of Operation BULL and Operation ROCK.[44]
S0489 WolfRAT

WolfRAT can record call audio.[45]
S0318 XLoader for Android

XLoader for Android covertly records phone calls.[46]

Mitigations

ID Mitigation Description
M1006 Use Recent OS Version

Android 9 and above restricts access to microphone, camera, and other sensors from background applications.[47]

M1011 User Guidance

Users should be wary of granting applications dangerous or privacy-intrusive permissions, such as access to microphone or audio output.

Detection

ID Data Source Data Component Detects
DS0041 Application Vetting Permissions Requests

Android applications using the RECORD_AUDIO permission and iOS applications using RequestRecordPermission should be carefully reviewed and monitored. If the CAPTURE_AUDIO_OUTPUT permission is found in a third-party Android application, the application should be heavily scrutinized.

In both Android (6.0 and up) and iOS, the user can review which applications have the permission to access the microphone through the device settings screen and revoke permissions as necessary.

DS0042 User Interface System Settings

In iOS 14 and up, an orange dot (or orange square if the Differentiate Without Color setting is enabled) appears in the status bar when the microphone is being used by an application. However, there have been demonstrations indicating it may still be possible to access the microphone in the background without triggering this visual indicator by abusing features that natively access the microphone or camera but do not trigger the visual indicators.[48]

In Android 12 and up, a green dot appears in the status bar when the microphone is being used by an application.[49]

References

  1. Google. (2021, August 11). Manifest.permission. Retrieved September 22, 2021.
  2. Android Developers. (2022, March 17). Voice Call. Retrieved April 1, 2022.
  3. Apple Developers. (n.d.). Requesting Authorization for Media Capture on iOS. Retrieved April 1, 2022.
  4. P Shunk, K Balaam. (2021, October 28). Rooting Malware Makes a Comeback: Lookout Discovers Global Campaign. Retrieved February 6, 2023.
  5. Lukas Stefanko. (2023, May 23). Android app breaking bad: From legitimate screen recording to file exfiltration within a year. Retrieved December 18, 2023.
  6. Lookout. (2016, May 25). 5 active mobile threats spoofing enterprise apps. Retrieved December 19, 2016.
  7. Dela Paz, R. (2016, October 21). BITTER: a targeted attack against Pakistan. Retrieved March 1, 2024.
  8. M. Feller. (2020, February 5). Infostealer, Keylogger, and Ransomware in One: Anubis Targets More than 250 Android Applications. Retrieved September 25, 2024.
  9. Kyle Schmittle, Alemdar Islamoglu, Paul Shunk, Justin Albrecht. (2023, April 27). Lookout Discovers Android Spyware Tied to Iranian Police Targeting Minorities: BouldSpy. Retrieved July 21, 2023.
  10. Alexey Firsh. (2018, August 29). BusyGasper – the unfriendly spy. Retrieved October 1, 2021.
  11. Stefanko, L. (2023, January 10). StrongPity espionage campaign targeting Android users. Retrieved January 31, 2023.
  12. A. Kumar, K. Del Rosso, J. Albrecht, C. Hebeisen. (2020, June 1). Mobile APT Surveillance Campaigns Targeting Uyghurs - A collection of long-running Android tooling connected to a Chinese mAPT actor. Retrieved November 10, 2020.
  13. T. Bao, J. Lu. (2020, April 14). Coronavirus Update App Leads to Project Spy Android and iOS Spyware. Retrieved April 24, 2020.
  14. Marc Rogers. (2014, March 6). Dendroid malware can take over your camera, record audio, and sneak into Google Play. Retrieved December 22, 2016.
  15. A. Blaich, M. Flossman. (2018, April 16). Lookout finds new surveillanceware in Google Play with ties to known threat actor targeting the Middle East. Retrieved September 11, 2020.
  16. Viral Gandhi. (2017, January 12). Super Mario Run Malware #2 – DroidJack RAT. Retrieved January 20, 2017.
  17. B. Toulas. (2022, March 12). Android malware Escobar steals your Google Authenticator MFA codes. Retrieved September 28, 2023.
  18. A. Bauer. (2019, April 8). Lookout discovers phishing sites distributing new iOS and Android surveillanceware. Retrieved September 11, 2020.
  19. Security Without Borders. (2019, March 29). Exodus: New Android Spyware Made in Italy. Retrieved September 3, 2019.
  20. Igor Golovin. (2022, April 11). Fakecalls: a talking Trojan. Retrieved July 21, 2023.
  21. Blaich, A., et al. (2018, January 18). Dark Caracal: Cyber-espionage at a Global Scale. Retrieved April 11, 2018.
  22. Actis B. (2017, April 22). FlexSpy Application Analysis. Retrieved September 4, 2019.
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  24. R. Iarchy, E. Rynkowski. (2018, July 5). GoldenCup: New Cyber Threat Targeting World Cup Fans. Retrieved October 29, 2020.
  25. E. Xu, G. Guo. (2019, June 28). Mobile Cyberespionage Campaign ‘Bouncing Golf’ Affects Middle East. Retrieved January 27, 2020.
  1. A. Hinchliffe, M. Harbison, J. Miller-Osborn, et al. (2018, March 13). HenBox: The Chickens Come Home to Roost. Retrieved September 9, 2019.
  2. Agranovich, D., et al. (2022, April). Adversarial Threat Report. Retrieved April 2, 2024.
  3. Apurva Kumar, Kristin Del Rosso. (2021, February 10). Novel Confucius APT Android Spyware Linked to India-Pakistan Conflict. Retrieved June 9, 2023.
  4. Bauer A., Kumar A., Hebeisen C., et al. (2019, July). Monokle: The Mobile Surveillance Tooling of the Special Technology Center. Retrieved September 4, 2019.
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