In Volume XII of Symantec’s *Internet Security Threat Report, Symantec noted that six of the top ten new malicious code families spread through file-sharing applications.
The report is available for download since Sept. 17th in PDF format at http://www.symantec.com/business/theme.jsp?themeid=threatreport
*The Symantec Internet Security Threat Report offers analysis and discussion of threat activity over a six-month period. It covers Internet attacks, vulnerabilities, malicious code, Phishing, spam and security risks as well as future trends.
View also their related blog entry on the above, entitled “What Are You Sharing?” at http://www.symantec.com/enterprise/security_response/weblog/2007/10/what_are_you_sharing.html