A new Worm called Sobig-E is running out wild in the net! It spread's out via networks or using it's own mail engine to sent a copy of itself to all mail adresses it finds on your computer. Hit "Read More" for virus info, removal tools and free online scanners. Symantec Sobig-E Removal Tool
Trendmicro free Online Virus-Scanner To prevent being infected by any type of virus make sure your incoming E-Mails are scanned with an Antivirus program (using the most recent updates) .
It's alway good to have all the latest security patches/fixes from MS installed.
Or use Opera instead of Internet Explorer + Outlook because Mozilla/Opera are not affected by most of the security problems IE/Outlook have