Android exploit tricks users into recording their screen

An Android exploit has been discovered which tricks users into recording their phone's screen without their knowledge.

A report by MWR InfoSecurity found the exploit and noted it affects smartphones running versions of Google's mobile operating system between Android 5.0 Lollipop and Android 7.1 Nougat.

The exploit uses Android's Media Projection framework, which was launched with Android 5.0 Lollipop and allows developers to record phone screens in addition to recording audio. With Media Projection, screen recording apps are no longer required to run with root privileges or signed with special keys as they did in versions prior to Android 5.0 Lollipop.

Normally with the Media Projection framework, an app asks for permission to the service through an intent that displays a SystemUI pop-up, informing the user that it wants to record the user's screen.

However, according to MWR InfoSecurity, an attacker is able to overlay the popup, tricking users into giving the app, and the attacker, permission to record the user's screen due to the inability of newer Android versions to detect fake SystemUI pop-ups.

The report states that although the vulnerability was fixed in Android 8.0, the majority of Android devices are still vulnerable. In fact, according to the Android Dashboard, 77.5% of Android devices are using versions between Android versions between 5.0 to 7.1.

While it is unclear if Google will release a patch for the exploit for the older affected versions of Android, the report suggests that developers enable FLAG_SECURE layout parameter in the app's WindowManager to secure the content of the app's window and to prevent it from showing up in screenshots and from being viewed on non-secure displays.