Why are ads popping up on my phone..?

[AC Question]

My phone restarts, pops up ads and downloads random games, When it restarts it shows a message saying " Android is Upgrading " I'm pretty sure this is when it downloads all the games. The games also force opens and interupts whatever im doing. The ads pop up EXACTLY at 12 A.M.. Weird huh, And to make it even more difficult to understand is that I've even FACTORY RESET my phone and it still doesn't work!! I really need help.. (btw my phone is not allowed to download from unknown sources

 

[B. Diddy]

Welcome to Android Central! Which phone? Does this happen in Safe Mode? On most Android devices, while powered on, press and hold Power until the Power Off menu appears. Press and hold the Power Off selection until the Safe Mode prompt appears. Tap OK.

If the problem disappears in Safe Mode, then something you installed is causing the problem. You may have to uninstall apps one by one until the problem disappears. If the problem persists in Safe Mode, then it's more likely to be a hardware or firmware problem.