I don't use any router 🙂 WIFI disabled ALWAYS (except to dowload a program on Apple Store ...)
Full updated and full option Locked except the minimum required for the Iphone to work well ....
Didn't install anything for months, except PoGo two days ago ... and the problem pop in the night yesterday ... it happened to thousand peoples at the exact same time all over the world .. Read the different forum linked one to another (sorry for crap english, not native as you noticed ...)
Someone reported in a forum that it happened when he downloated the apk from another source, i don't do that, was from regular store since my Iphone is not modified ..
The site i tested (they are two in fact ..) are safe, i use them for age and are poor french site for encouter that no one know out from France ^^ they are not infected by the night ! lol ... anyway .. that's ANY SITE that you open and the Crap POP ....If you want my feeling,... I think exactly like you, the Iphone CAN NOT be infected except from a Corrupted Program installed by user .. So this means, some Pokemon Go (or all i don't know...) where corrupted incluing the Crap .. That's the ONLY way i see, because what happened is not on a web site, it's definitively IN THE PHONE NOW ..
I don't see any other reasons i could have been contaminated, i did not click on anything on the redirected crap site, only closed ...
Once again, it happens at the very same time to Thousands peoples all over the World !! See the date on forums, nothing before .... All from this night .... And if i was a piwate myself, i would really choose Pokemon Go to put my Crap, best option ever with the millions download ... You know they already been victim of an attack yea ?? They are just noobs in all this and can easy be corrupted my feeling ...
Well, just hope APPLE give us a Fix Assap ..
Regards