The messenger spam has been around for at least 6 months now. It is amazing that Blue is only seeing it now. I just turned that service off for a friend last night.
I started getting that last fall. But once I killed the service, no more problems. I've been using Norton Firewall for a few months now and it's pretty low maintenance. I would have gone with Zone Alarm, but for some reason the trial version would lock up my win2k box completely (I had to go into safe mode to remove it). So Zone Alarm made things a little TOO secure.