Posted by Virus Bulletin on Mar 27, 2013
Spam more of a challenge for majority of products.
The results of VB's latest spam filter test show that spam has become more difficult to filter - with 15 of the 19 products missing more spam than they did in the last test.
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.
It would be easy to suggest that the developers of the spam filters are slacking, but it is likely that the reason behind the drop in catch rates is that more spam is being sent in ways that make it harder to block. According to one recent report, a lot of spam is now being sent through compromised hosts rather than the traditional source of vast chunks of spam, compromised home PCs.
There was some good news, however: 17 full solutions reached the required standard to achieve a VBSpam award, and two of them - Libra Esva and Bitdefender - combined a very high catch rate (99.50% or more) with a lack of false positives and thus earned VBSpam+ awards.
This test also saw the return of a phishing feed provided by Wombat Security Technologies. As had already be seen last year, most products find phishing emails far more difficult to filter than standard spam, with the majority of products missing at least 10% of these emails. Given the potential consequences of failing to recognize a phishing email as such, there is certainly room for improvement here.