It's apparently a Trojan horse that attacks mobile devices and specifically through message boards. It gets progressively worse until you can't click on a thread without being redirected and then taken to iTunes (or similar - this attacks android devices too) and asked to purchase the game "Candy Crush". I've been dealing with this for months now and it's really gotten terrible lately. There are no known fixes except for the MB hosts to cancel all advertising from King.com. At least this is what I've been able to glean from the multiple threads I've found on this through google.