Both for me. For a couple weeks on computer I've had this white "ad" box following my cursor all over. I've tried the normal tricks and nothing worked. Now this Norton thing is a pain because it says I have threats and need to click their buttons, ah no I close the window. It has been going on for about 4 days or so.
It started on my iPhone today. Almost every time I tried to open I get a huge window, ATT winner,
Walmart winner .. again I can not close it must close entire window. Literally just happened again.
Really aggravating, may be best to step away a few days and hope they fix it.