Rogue applications are an unfortunate part of reality for Android. Even though they are certainly not exclusive to Google’s mobile operating system, it almost seems as if there are more Android-based ones, seeing how many security researchers continually report malware. To help fight back, Google included a feature within Android 7.1 Nougat that has flown under the radar, but kicks users exit out of malicious apps.
XDA Developers features a thorough breakdown of the feature, but the general idea is that “panic detection” pays attention to how many times you press the back button within a certain amount of time. This is in order to differentiate a regular button press from the four button presses needed to activate the feature, with 0.3 seconds per tap acting as the grace period during which panic detection checks for further key presses.
This allows the operating system to override the app and send you back to the home screen, particularly useful if a rogue app takes over the display and prevents you from backing out of it. From there, you can uninstall the malicious app and be on your merry way.
Google does not advertise this feature for one reason or another, but it is very useful for those who accidentally download a malicious app. Then again, the number of folks not on Android 7.1 greatly number the number of people who are. Panic detection is also a feature that hackers will try to exploit and, as such, try to keep it from working so people remain stuck in their scam apps.