Android Trojan removal
After reading this, Iwent and saw on my phone that /system/app contains folders for Google apps, more likely the stock apps. 
Make a backup of the phone (backups only include apps from the play store and other data) and wipe it. You may need to obtain an image file for your phone, install a recovery like TWRP or CWM, wipe the system partition, and install the os image and restore.