The majority of the world's e-mail is spam, says a Commtouch report. According to the company's spam trends report for the first quarter of 2007, 85% to 90% of all global e-mail is spam.
The research report is based on real-time analysis of billions of messages sent globally each week.
The company says global spam rates temporarily dropped a few percentage points after the Christmas holiday season, but climbed back up by the end of the quarter.
Zombies were detected in over 100 countries, having spread to almost every corner of the globe. The top spam subject was sexual enhancers, with stock pump-and-dump scams in second place.
"Massive botnets continue to be the force behind most global spam," says Commtouch president and CTO Amir Lev.
He says solutions that attempt to detect spam by scanning individual messages for content are inundated by the spam floods the botnets generate. Effective protection against spam requires dynamic blocking at the network perimeter, based on the reputation of the sender, he says.
Newsletter trick
Commtouch says spammers' latest trick is to hijack legitimate newsletters to confuse anti-spam solutions.
Spammers commandeer a popular e-mail newsletter and insert their spam image at the beginning of the message. This trick gets the malevolent message past many anti-spam solutions by cloaking itself as a legitimate e-mail newsletter.
URL blockers, Bayesian filters, and image-analysis technologies have been blindsided by this new technique of hiding spam within a real e-mail newsletter.
Lev says fighting spam on a trick-per-trick basis is futile. The spammer innovation cycle is so fast and sophisticated, that as soon as traditional anti-spam solutions come up with a way to block the latest trick, the spammers have already thought of something new, he notes.
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