1) Check if they're online when the link is sent to you.
2) If they are, ask them if they sent that to you and what it is.
3) If they don't reply, ignore the link.
4) Even if they reply, sometimes it has a scripted response. Best way to find out if they're scripted is to ask them something ridiculous like how big their mom's tits are (the bot won't have a response for this - your friend will!)
If you know for a fact that YOU have been infected with this crap, remove all your apps and post a message on your wall saying so - that way your friends will be warned should "you" send them a dubious link.
Also, Facebook support is utter shit. Having to go send in a form that you can't add details to is stupid. Would be better if you could email their support staff or something.