After 30 days, many AV vendors cannot detect known attacks

Cyveillance testing finds AV vendors detect on average less than 19% of malware attacks

Even after 30 days, many AV vendors cannot detect known attacks, making it critical for enterprises to take a more proactive approach to online security in order to minimize the potential for infection.

http://www.cyveillance.com/web/news/press_rel/2010/2010-08-04.asp