Hopefully, most companies and individuals are up-to-date on Microsoft security patches.  This new exploit has just been developed from the MS05-011 security bulletin published in February. It could be adapted for use in future computer viruses and worms. 

MS05-011 - Exploit Code to attack SMB vulnerabilities published
http://isc.sans.org/diary.php?date=2005-06-23

QUOTE: FrSIRT has published exploit code for the recent flaw in Microsoft Server Message Block (SMB). The advisory and patch related to this vulnerability were released on February 8th, 2005. If you still have not patched, you are further urged to do so in light of the release of exploit code.

FfSIRT - Published exploit (be care as POC code is here)
http://www.frsirt.com/exploits/20050623.mssmb_poc.c.php