Antivirus News

There are hundreds of millions of spam email messages being sent every
day. This has been a significant problem as spam covers 90% of all emails
worldwide. Now this has become an even bigger challenge due to increased
volume of image spam.

Image spam is a serious and growing problem, not least because of its ability
to circumvent traditional email spam filters to clog servers and inboxes. In
just half a year, the problem of image spam has become general enough to be
representative of 35 per cent of all junk mail. Not only this, but image spam
is taking up 70 per cent of the bandwidth bulge on account of the large file
sizes every single one represents.

Apart from taking up valuable bandwidth, the time taken to filter out and
destroy spam represents a significant burden on both IT staff and personnel
in businesses and organizations. At the same time, operators themselves are
building ever more efficient email servers and bandwidth capacity in order to
deliver emails that nobody wants!
 
Ironically, at the heart of the problem are ordinary computer owners
completely unaware that their computers are being used to launch the very
attacks that end up in their inboxes. This is achieved through botnets, where
computers are silently infected and activated as part of a larger raft of
computers to do the spammers’ bidding. Vast majority of all the spam is being
sent from these botnets of zombie computers.

To give some idea about the scale of the problem a typical Warezov-based
botnet can send 160 million spam messages in just two hours. And last year
botnets raised the volume of spam in circulation by 30 per cent. For
enterprises, often the target of spam attacks, that figure was 50 per cent.

Spam originally used basic text captured in a GIF image to bypass standard
dictionary-based content filters but this has now morphed into image spam.
Image spam is characterized by patchwork colours, multicolour characters with
pixel-level randomization. It also features the use of random nonsensical
text messages sampled from legitimate web sites between the hard sell of
products like Viagra and other popular pharmaceuticals.

In the war against this new menace are ever-more efficient spam filters. In
practice, all of the most recognized spam filter systems have upped their
game in order to deflect these new techniques. Technology aside, Mikko
Hypponen, Chief Research Officer at F-Secure believes there is a larger issue
to address - people themselves: “We will never rid ourselves of spam until
people stop buying the products advertised in these mails. Spam obviously
works, otherwise we would not see it so prevalently,” he concluded.

F-Secure Messaging Security Gateway has a unique approach to combat
image-based spam, and uses several advanced techniques specially designed to
detect image-based spam messages. These improved techniques in
Proofpoint-powered MLX include fuzzy matching for obfuscated images, dynamic
spam image detection, animated GIF spam detection and dynamic botnet
protection. Using these image-based spam specific techniques with other
existing spam detection techniques with fully automatic updates, F-Secure
Messaging Security Gateway is able to provide comprehensive solution to it’s
customers.