I just recently got the same error on my Sony Xperia Z5 Compact (USA).
The URL starts with data:text/html;base64,PCF
"Congratulations [ISP] services user, you have been chosen for a change to get a new iPhone 6s, Macbook, Ipad, etc)"
There is no way to exit unless you delete the cache in the Apps setting.
The message will go away but will come right back up after browsing through different sites. (Bestbuy.com, cnn, random google searches, etc)
I have done the following:
Phones Factory Reset (wipe everything)
Deleted all cache, cookies, history, etc since the beginning of time on my Google browsers (on all devices).
Those didn't work.
I removed my SD card, I then did a full Flash ROM re-install (Wipe'd everything using FlashTool) and i still get the blasted error message.
This occurs on any network (Home, Work, Cellular, etc)
I do not visit any dodgy websites nor have i downloaded any apps recently. I am not at all sure what is going on here.
I've currently signed out of my Google account on my phone and i'll see if that makes a difference to narrow thins down.
*It's not my network, nor the phone, my guess here is some plug in with my Google account.
08-25-2016 02:39 PM