News
Virus Bulletin finds spam filters are blocking less spam
March 2013 by Virus Bulletin
Virus Bulletin, the independent security certification body, has
announced the results of its latest anti-spam comparative
review: 17 solutions achieved a VBSpam award, but the majority
did so with a lower spam catch rate than in recent tests.
Nine out of the 19 full solutions tested saw the percentage of
spam they missed at least double, with only three products
improving their catch rates. A spam email was almost twice as
likely to make it to a user’s inbox compared to the previous
test.
Most products had more difficulty with legitimate emails as
well, with only four solutions correctly identifying all of
them, and products had even more difficulty blocking phishing
emails. More than half of the solutions missed at least 10% of
the emails in a dedicated feed of phishing emails.
"Spam has been a relatively good news story in recent years,
with spam levels declining while catch rates remained high,"
said VB’s Anti-Spam Test Director, Martijn Grooten. "But in spam
filtering, the devil is in the details, and when we look at
these details, we see more emails slipping through the maze."
This is not the first time Virus Bulletin has observed a drop in
products’ spam catch rates: a similar drop was observed early
last year, with the decline continuing throughout the first half
of the year.
Grooten continued: "It is obvious why missing a phishing email
is bad and could have serious consequences, but even an ordinary
spam email can be much more than a nuisance in the inbox. A lot
of today’s spam has malware attached or links to exploit kits
and it just takes one click on a link in an email that shouldn’t
have been there to grant cyber crooks access to your PC or
mobile device. We will be keeping a close eye on spam catch
rates, and hoping that the filters manage to catch up more
quickly this year."
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-0313-1200.jpg
(journalists are permitted to reproduce this chart unedited).
The results of the March 2013 anti-spam comparative review can
be seen at http://www.virusbtn.com/vbspam/archive/test?id=185
The full review, including detailed results tables and analysis,
is available to Virus Bulletin subscribers or can be purchased
as a standalone review ($19.95) from
http://www.virusbtn.com/vbspam/archive/list
