AV-Test is not as well-known in the United States as it should be, possibly because the group is located in Germany at the Otto von Guericke University Magdeburg. Andreas Marx, manager of AV-Test, provided test results showing how long it took 23 major anti-virus programs worldwide to come up with new signature files during the past several weeks. The new signature files involved in the test were developed to fight four novel viruses that weren’t being caught by the preventive or “heuristic” techniques of most anti-virus programs. These four new viruses are known as Dumaru.Y, MyDoom.A, Bagle.A and Bagle.B.
AV-Test uses special scripts to check the servers at anti-virus companies every five minutes, looking for new signature files.
  H:M     Anti-Virus Program
  06:51   Kaspersky
  08:21   Bitdefender
  08:45   Virusbuster
  09:08   F-Secure
  09:16   F-Prot
  09:16   RAV
  09:24   AntiVir
  10:31   Quickheal
  10:52   InoculateIT-CA
  11:30   Ikarus
  12:00   AVG
  12:17   Avast
  12:22   Sophos
  12:31   Dr. Web
  13:06   Trend Micro
  13:10   Norman
  13:59   Command
  14:04   Panda
  17:16   Esafe
  24:12   A2
  26:11   McAfee
  27:10   Symantec
  29:45   InoculateIT-VET 
Although new signatures are sometimes posted very quickly in special cases, many major anti-virus services schedule regular online updates only once or twice a week, AV-Test says. Other providers, such as F-Secure, schedule updates seven times a week, while Kaspersky Labs schedules them 20 times a week, according to AV-Test’s figures.
Kaspersky schedules new signature files the most often — and earned the fastest average response times in AV-Test’s real-time trials, shown above — because the company has a large number of people around the world analyzing viruses and developing cures, Holdsworth says.
More info: http://itmanagement.earthweb.com/columns/executive_tech/article.php/3316511