SANS - Internet Storm Center - Cooperative Cyber Threat Monitor And Alert System - Current Infosec News and Analysis
This is the reason for all the 445 traffic lately.
"Updated August 14th 2005 18:34 UTC
MS05-039 Worm in the wild
-039 is NOT Microsoft's lucky number"
For home and corporate networks with Microsoft computer, it would be better to just disconnect from the web until you can get an expert to protect the network. If you need an expert just call. ;)