Instant Messenger Viruses?

WARNING DO NOT CLICK ON THE LINK

The strangest thing happened today. I was using IM when the following message came through:

“From John Charles: Is this really you???!!! http://pictures.templates4friends.com/pictures.php?email=myaddress.com ”

Because the email came from ‘John’ who is our security guy at my ISP, I didn’t even stop to check if anything was unusual. Anyway, when I clicked on the link it tried to download a virus onto my machine!

I quickly called John to see if he knew and he said the same thing happened to him and before he realised, he was infected!

Now I’ve heard of viruses coming via attachments on IM, but as a link? John said he’d never seen this before.

Has anyone else seen this before?