Seeking for advice

[appninza]

Hi, my friend recently bought a Samsung galaxy s8. I don't know what he did with it but there are ads everywhere in device(even after hard reset). How to get out this problem?

 

[B. Diddy]

I moved this from the Android App Inventor forum (not sure why it was there) to the General Help forum.

After he did the factory reset, did he let it restore from a previous backup? Tell him to try another factory reset, and this time, don't restore from a previous backup -- set it up as a brand new phone, and don't install any apps yet. Does the problem persist?