1. do you have a list of all the apps you have installed?
2. when you say you did a factory reset, and it didn't change, did you reset, log into google account, wait for it to sync, then you noticed nothing changed? because if so, it's most likely an app causing it. and once you logged in and sync'd your apps, you're right back to where you were before the wipe.
3. you don't have an anti-virus or anything like that installed, do you?