Sounds like some kind of exploit has compromised the Android operating system itself. Keep in mind a Factory Reset only wipes the general user data partition, /data. It does not have any affect to any of the system partitions. All a Factory Reset does is clean out user data and user installed apps, things stored in /data. Just like a rooted phone will remain rooted after a Factory Reset, or an un-rooted phone will remain un-rooted after a Reset, a compromised operating system will remain compromised too. Most exploits are limited to user level things, they can only mess with files, apps, and services that you the user have installed. More insidious exploits however, can insert themselves into the operating system. If something like that has infected your device, chances are it is a system level issue so no matter how many times you restart or Factory Reset it the problem will remain. Also note that any anti-virus/anti-malware utility you install from the Play Store will be installed as a general user so they all have only limited capabilities to clean out system-level infections. The only reliable way to fix you problem is to re-flash the stock ROM. Flashing a ROM is essentially the same as doing a re-install of the operating system on a computer.
05-31-2017 03:04 PM