Reprinted under permission from the Aladdin Knowledge Systems CSRT (Content Security Research Team).
http://www.esafe.com/home/CSRT
While this year was marked by the most destructive and clever Klez virus, if we look back we can clearly see there have been no other major outbreaks and the entire virus-making "industry" is on the decline. Klez ruled the top ten viruses this year and very far behind it were threats such as Lentin and the Frethem family. This list is dwarfed when compared to last year's most notorious threats: Badtrans, Code Red, Hybris, Nimda and last year's "champion" - SirCam.
The reasons for this decline are speculated to be the result of increased awareness of the subject. On one hand, Internet users tend to be more cautious, many of them recognizing potential virus infections by sight alone. On the other hand, the anti-virus industry has learned a great deal from last year's experience and nowadays the protection offered by anti-virus software became much more effective. As a result, virus makers have to work harder in order to create actual threats - ones that can fool both users and software.
One must always keep in mind, however, that better security means less criminals - but the ones left only try harder.