I just got an Alert via MSN Messenger McAfee tab about the W32/Bugbear@MM worm
W32/Bugbear@MM is rated as MEDIUM RISK FOR HOME AND CORPORATE USERS. This mass-mailing worm attempts to send itself to email addresses found on an infected system.
Once the virus is run, it will attempt to disable various security products, including many forms of anti-virus and personal firewall protection. It will also attempt to install a backdoor trojan that can capture what the user types, including sensitive information such as passwords.
This virus spreads via email and via network shares. It makes use of the Incorrect MIME Header Can Cause IE to Execute E-mail Attachment vulnerability in Microsoft Internet Explorer (v 5.01 or 5.5 without SP2).
Simply opening or previewing an infected message in a vulnerable email reader can result in infection.