I reckon it's the ad network. Somebody who writes the JavaScript probably missed a semicolon or parenthesis. Are you on Android? Firefox works on mobile and supports uBlock (don't use Adblock, they have a gross "acceptable ads" program which they are using to sell advertising space on other peoples websites).
Ad networks are a main malware payload route it seems. All sorts of legitimate sites will suddenly pop up into App Store and try to run other malicious code. It's really difficult to prevent and makes using an Adblock service almost mandatory. People who sell ads don't really seem to care and a bad ad can run for weeks before it gets pulled
It's an Android and I use Chrome on it. I have Firefox on my Linuxbox with U-Block and I am happy with it. If you think it's a good idea, I'll look into doing the same for my phone, though I didn't know you could get adblockers for phones. I wonder how well they work/use up wireless data.