The algorithm used in one of the most debilitating email worm attacks in history <A HREF="http://www.eweek.com/article2/0,1895,1899776,00.asp?kc=ewnws121205dtx1k0000599">has been cracked,</A> allowing virus researchers to accurately predict the dates and URLs that will be used in future mutants. Researchers at Finnish anti-virus vendor F-Secure first cracked the code used in the Win32.Sober worm family in May this year but withheld details until this week to avoid tipping off the attacker.