The number of signatures required to detect malicious code skyrocketed
in the first half of 2008, increasing by 80 percent since the end of
2007, according to data released by antivirus firm F-Secure on Tuesday.
The data -- part of the F-Secure's IT Security Threat Summary
-- showed that the company currently requires nearly 900,000 different
signatures, also referred to as "definitions" or "detections," in its
product to catch current threats, up from 500,000 signatures at the end of 2007.
http://www.securityfocus.com/brief/763