We've seen some MSN Messenger worms being spread around this weekend.

Once you get infected, your Messenger will start to send web links to all of your contacts. If they follow the links and download the prompted programs, they'll get infected too.

One of them (detected by us as Trojan.Win32.Agent.DWD) sends links titled "nakedfamily" or "naked4friends", and shows this image on your desktop once you get infected: