How did you know that it was jacked? Did you see a process running excessively in the background? And you said by adding nocoin to your browser it stopped, so was it being run as a script?
Cryptojacking is actually pretty common. They tend to mine Monero, because that still gives them rewards if it's done on a very large scale.
The people who are running the malware could have up to 100k slave computers in their network, generating them thousands of dollars per day/week.
It's usually pretty easy to notice too, when your CPU goes through the roof.
Running noscript is also a solution btw.
Yeah actually I think one of my browsers fell victim to it now that you mention it. It wasn't too bad, but I noticed higher than usual load times and it was quite slow with page load times. CPU wasn't excessively high, but more than normal. I just installed nocoin so will see if there's much of a difference.
I saw this the other day at the bottom of the page at the Pirate Bay:
"By entering TPB you agree to XMR being mined using your CPU. If you don't agree please leave now or install an adBlocker"
It's like giving permission for cookies. What a crazy world we live in now.
At least they talk to their users about it, even the way to keep using the site while blocking cryptocurrency mining. Besides, it's better than seeing tons of ads.