I think my rooted cyanongenmod phone was hacked. What can I do to start fresh again? I already did a factory reset but after 1 month the phone started acting weird again (battery time dropped significantly, home screen mysteriously changes, unexpected reboots of the phone and the other day I saw that my phone was rebooting and installing something that looked weird at 3 am).
My phone is a Samsung Galaxy Nexus I9250 if that matters.
Should I format SD card also?