Adversaries may use screen captures to collect information about applications running in the foreground, capture user data, credentials, or other sensitive information. Applications running in the background can capture screenshots or videos of another application running in the foreground by using the Android
MediaProjectionManager (generally requires the device user to grant consent). Background applications can also use Android accessibility services to capture screen contents being displayed by a foreground application. An adversary with root access or Android Debug Bridge (adb) access could call the Android
Monokle can record the screen as the user unlocks the device and can take screenshots of any application in the foreground. Monokle can also abuse accessibility features to read the screen to capture data from a large number of popular applications.
|Application Developer Guidance||
Application developers can apply
Applications can be vetted for their use of the Android MediaProjectionManager class, with extra scrutiny applied to any application that uses the class.
Enterprise policies should block access to the Android Debug Bridge (ADB) by preventing users from enabling USB debugging on Android devices unless specifically needed (e.g., if the device is used for application development). An EMM/MDM can use the Android
Users should be advised not to grant consent for screen captures to occur unless expected. Users should avoid enabling USB debugging (Android Debug Bridge) unless explicitly required.
The user can view a list of apps with accessibility service privileges in the device settings.
- Dario Durando. (2019, July 3). BianLian: A New Wave Emerges. Retrieved September 4, 2019.
- Android Developers. (n.d.). Android MediaProjectionManager. Retrieved August 8, 2019.
- Bauer A., Kumar A., Hebeisen C., et al. (2019, July). Monokle: The Mobile Surveillance Tooling of the Special Technology Center. Retrieved September 4, 2019.
- Android Developers. (n.d.). Android Debug Bridge (adb). Retrieved August 8, 2019.
- Zhang, V. (2015, July 21). Hacking Team RCSAndroid Spying Tool Listens to Calls; Roots Devices to Get In. Retrieved August 8, 2019.
- FlexiSpy. (n.d.). FlexiSpy Monitoring Features. Retrieved September 4, 2019.
- Wenjun Hu, Cong Zheng and Zhi Xu. (2017, July 6). SpyDealer: Android Trojan Spying on More Than 40 Apps. Retrieved September 18, 2018.
- Security Without Borders. (2019, March 29). Exodus: New Android Spyware Made in Italy. Retrieved September 3, 2019.