I got a popup today taking me to one of those "You've won a free gift card!" pages.
Not sure if it's this site as you mention, or another site that might have a bad embedded advert.
Yep, I got something like that when clicking on a "go to last post button". It started doing a redirect to some site so I closed it immediately. The malicious address is gs.artltoken
Logging out of the forum until this is fixed.