An ad screen appears on iOS, what could it be?

Question

JavaScript

iPhone 6 iOS 8.4 an advertising screen pops out, according to the victim, it can pop up during a call or when using a browser (Chrome), apparently at random times.
Unfortunately, there is only a screenshot with a screen, there is no more information yet (it will be when I take the phone from him). I've never seen anything like it. I can only assume that the victim has some kind of widget or keyboard that pushes this screen to the controller. But this is all speculation, does anyone have any information about what it could be?

Screenshot

UPD: no
jailbreak

Answer 1

Add a check on event.type for example. If it's a mouse, then the first condition, if it's a keyboard, then the second.

Answer 2

How do you hang a keyboard and mouse for one event?

Answer 3

This is ussd - tear your head off your operator

Answer 4

Has a jailbreak been made?