Virus Bulletin finds spam filters are blocking less spam
March 2012 by Marc Jacob
Virus Bulletin, the independent security certification body, has
announced the results of its latest anti-spam comparative
review, which saw 20 solutions achieve a VBSpam award - but the
majority displayed significantly lower spam catch rates than in
other recent tests.
Overall, products’ spam catch rates were significantly lower
than in previous months, in many cases products missed more than
twice as much spam as in previous tests.
"This is a worrying trend," says VB’s Anti-Spam Test Director
Martijn Grooten. "There have been many news stories highlighting
a global decline in spam in recent months, but if spam filter
performances decline too, the situation for the end-user doesn’t
improve at all."
Grooten continued: "It is hard to say what exactly caused
filters to miss more spam, but it looks like spammers are doing
a better job at avoiding IP- and domain-based blacklists. It may
be a sign that they are increasingly using compromised
legitimate systems to send their messages."
The best performance in this month’s test came from Libra Esva,
which blocked 99.97% of all spam messages without blocking any
legitimate mail, and as such was the only product to obtain the
new ’VBSpam+’ award (to qualify for the VBSpam+ award, products
must achieve a spam catch rate that is higher than 99.5% and a
zero false positive rate).
The VBSpam quadrant plots products’ spam catch rate against
their false positive rate, with the top right-hand corner the
area products should be aiming for (with maximum spam catch rate
and minimum false positive rate). The front-runners in this test
can clearly be seen from their positions on the quadrant at
http://www.virusbtn.com/vbspam/charts/vbspam-chart-0312-1200.jpg
(journals and websites are permitted to reproduce this chart
unedited).
The results of the March 2012 anti-spam comparative review can
be seen at http://www.virusbtn.com/vbspam/archive/test?id=173
The full review, including detailed results tables, is available
to Virus Bulletin subscribers or can be purchased as a
standalone review ($19.95)