Sunbelt - Growth of Malware Statistics
As reflected in the charts, malware continues to grow in volume, sophistication, and in numbers of variants (i.e., polymorphism). Technical safeguards and best practices are always required.
Sunbelt - Growth of Malware Statistics
http://sunbeltblog.blogspot.com/2009/05/growth-of-malware-update.html
Dramatic Increase due numerous variants within malware families
http://sunbeltblog.blogspot.com/2008/01/growth-of-malware.html