A new report by security vendor Commtouch claims attackers are increasingly spreading server-side polymorphic malware via email in a bid to circumvent antivirus tools.

According to the report, which focuses on the first four months of 2007, <A HREF="http://www.eweek.com/article2/0,1895,2125082,00.asp?kc=EWNAVEMNL050307EOAD">malware writers are using speed, variation and social engineering techniques</A> to mass-distribute their malicious code across the Web.