Be sure your Windows April security updates are in place.
Steve Gibson
Internet traffic watchers have been reporting an increase in traffic which they believe is a pre-cursor to a "Blaster style" Internet worm. This traffic appears to be probing computers for several of the vulnerabilities recently revealed by Microsoft's significant mid-April Windows security updates; specifically MS04-011, MS04-012, MS04-013...
Leggi:
http://www.grc.com/default.htm