I have Samsung Galaxy Note 2. suddenly it started showing up Factory mode screen and not getting registered on Airtel network or any other network. Also it's IMEI number in OS got changed compared to the one at backside of phone. Looks like some mobile virus. Any Idea how to repair IMEI number/ get Rid of Auto Factory Mode/ how to get registered to Airtel or any other network? i saw lot of articles, lot of things i tried but in vain.