Well some hackers managed to get their dirty fingers inside the server and injected a whole bunch of code that was bouncing people to Russian websites and prompting downloads of suspicious files. I'm not sure how they managed to do it, but thankfully backups have come in very handy and everything was able to be restored with minimal delay. There will be some lost content on the forum, but I hope nothing important was lost. Please let me know if you see anything broken and I'll look into it.
My sincere apologies for anyone who was inconvenienced, or happened to be tricked into marrying a Russian bride.
As a precaution I would suggest changing your forum password and choose one that is secure (no common words or number/letter combinations). The database wasn't compromised, but hey, it couldn't hurt.