Hi Michel,
It's not MSN it's built-in Windows Messenger Service. In particular, NET SEND uses it to send messages between Pc's.

>>Here's a story about this new type of spam http://www.wired.com/news/technology/0,1282,55795,00.html. To kill it you've to close port 135 in your firewall. The alternative is to stop Windows Messenger Service on your pc.
>
>That looks like a new patch is coming from MSN then. If it applies when it runs, then, there's something they have to fix in there.
>
>I also found those annoying since two weeks two.