I shouldn't worry too much about malware. It's more likely a server-side hack. Also, passwords are encrypted in the database with that particular forum package, so there is not much chance of them having your password.
They may have your email address, but that's not the end of the world, just redirect any mails from them to your junk email folder. Don't open any attachments from these clowns either.
Anonymous. A bunch of utter dickheads with no real point or cause. More of a nuisance than any real threat.
What's ironic is that it redirected you to some "important political video" which, of course, everyone ignored as spam. Way to make a point you ....... Nobody actually cared about whatever message they were trying to get across. Utterly idiotic in every sense.