The ever-changing Storm Worm is now circulating new variants.  I've personally started receiving copies captured in my spam filters.  The new version uses inappropriate subject lines as noted by the ISC below. 

Based on samples received these messages contain only URL with only a numeric IP address in the body of the email text.  URLs in spam email are usually always dangerous sources of malware (esp. numeric IP addresses). 

Users should avoid these new attacks as this virus is very difficult to clean and can affect both the privacy and performance of the PC itself.

http://isc.sans.org/diary.html?storyid=3286