I purchased a used Note 4 off ebay and want to make completely sure there are no spy apps or malware on it. I know some spy apps can be installed into the system partition and survive a factory reset. I discovered an app called cerberus that could do this and could be used to spy on me and blackmail me. How do I completely clean my phone of all spy apps or malware and completely wipe everything including the system partition erasing everything.
Cerberus is an anti theft app. It can be used to maliciously spy on you making it spyware. I don't know who has used this phone or where it has been anything could be on it.