Lockerpin is the first known Android lock-screen ransomware to set a phones PIN lock that is targeting mainly US mobile users. Most of the infected Android devices are in the USA (75%), with a percentage share of over 75 per cent. The app tricks users into granting it administrator privileges by displaying a bogus patch installation window on top of an activation notice. When victims click on the continue button, they grant the malicious app the administrator privileges which allow the app to modify the Android settings.”]
Source: http://securityaffairs.co/wordpress/40082/cyber-crime/lockerpin-android-ransomware.html