November 20, 2006 4:00 AM PST

'Tis the season to send spam

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SpamThru is unique because it uses peer-to-peer technology to share information with other compromised PCs. That information includes details on the control server, spam templates and all the peers each compromised computer knows about, a researcher at security company SecureWorks said.

Volume by size

The Trojan horse appears to be the handiwork of Russian programmers, SecureWorks added. Researchers found evidence that about 73,000 computers in 166 countries are part of the SpamThru botnet, adding up to a mighty spam cannon.

Avoiding blocks

At the same time, junk e-mailers have gotten better at tricking filters, experts said. The latest techniques rely on e-mails that are simple text or that carry only an image. In the pure text messages, key words are often misspelled to throw off filters. The image-based junk is tough to sift out, because many spam filters can't see what's in the image.

"Sophisticated spammers generally design and test their messages against the current spam definitions of popular spam filters," Pao said.

All that unsolicited e-mail eats up a lot of bandwidth and can clog e-mail servers, not to mention inboxes. Last month, all the spam sent worldwide added up to 819 terabytes per day in data, compared with 275 terabytes a year ago, according to IronPort's research.

"The problem is that spam filters, even very good ones, catch a certain percentage of the spam. Even if they catch 99 percent of the spam, 1 percent of a big number can still be a very big number (of e-mails that do make it through)," said Tom Gillis, senior vice president of worldwide marketing at IronPort in San Bruno, Calif.

The economic impact from time wasted deleting spam was estimated to be $21.6 billion in 2004, according to the National Technology Readiness Survey, an annual survey conducted by Center for Excellence in Service at the University of Maryland's Robert H. Smith School of Business and Rockbridge Assoc.

"E-mail users are getting very frustrated, and ISPs and enterprises are paying for a lot of bandwidth," Forrester analyst Lambert said.

The continued increase in spam and the challenges of dealing with it suggest that Microsoft Chairman Bill Gates' prediction two years ago, that the spam problem would be solved by now, has not come true. "Spam is definitely a continuing problem," Lambert said.

Spam fighters haven't thrown in the towel. Companies such as Barracuda Networks, IronPort and MessageLabs are working to strengthen their spam filters. At the same time, e-mail service providers and Internet service providers such as Yahoo are trying to keep consumer in-boxes clean through technology and initiatives such as Sender ID and DomainKeys Identified Mail.

For now, though, it looks like people will be getting a lot of junk in the Christmas season.

"The amount of spam has been increasing over the past year--especially around the holidays. Really, it will only get worse," Lambert said.

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antispam company, spammer, Ironport Systems Inc., spam, MessageLabs Ltd.

 

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