Filter: More ham, less spam

General Article
March 4, 2004

Starting this month, PureMessage will filter and reduce your daily deluge of incoming, unwanted e-mail

Sonja Outlaw, manager of server operations, and systems administrator, Robert McDermott spearheaded the spam-filter project. photo by Todd McNaught

By MATT BRIGGS

Do you receive an inordinate number of e-mail with subjects reading "Adv. Be.The.King.Of.Your.Bedroom,uxbiguvka?" Has Valencia B. Badger mailed you with the testimonial that "Over 1 million people have used our service, remputca?" If so, you've been spammed.

Many employees and affiliates at the center receive dozens of messages like these a day. A few users, such as Lynn Perkins, a project manager in Facilities and Planning, receive more than one hundred spam e-mails each day. The amount of spam delivered to Perkins has increased steadily for months. Although she tried a number of anti-spam programs, nothing seemed to help.

"I was at the end of my rope," Perkins said. "I started to collect my spam. I was angry. I measured it, put the numbers in Excel and charted their growth. Based on the increase in my sample, I figured I'd reach over a thousand a day by June 2004."

Perkins is not alone. On any given day, about 40 percent of the center's e-mail consists of spam. In the evenings and weekends, when center e-mail traffic falls, the number of incoming junk mail exceeds legitimate mail. But as of this week, employees should see some relief.

On March 1, Information Technology installed a spam filter called PureMessage. While the filter does not stamp out spam, once you set your options on the IT Web site, you should see a significant reduction in the amount of unsolicited e-mail.

"The new system works," said Jason Pitt, a graduate research assistant in Basic Sciences. "For the first month I didn't get any spam. And then, the last couple of weeks, I've received one or two a day."

Why spammers spam

Spammers make money by the volume of e-mail delivered to active e-mail addresses. Some spammers can send as many as a billion e-mails a day. Even if one out of a hundred thousand messages sent results in a purchase, they make a profit since it costs nothing to send messages.

Spammers acquire e-mail addresses in many ways. The most common, is to buy them. Once an e-mail address enters into the spam market it will be resold many times to different spammers.

As anti-spammers develop technology to prevent unsolicited mail, spammers develop new strategies to hit their targets. You could think of this as a spam arms race. Spammers send e-mail designed to slip through the first filters that just use keywords such as "Viagra." To sidestep this type of filter, spammers just misspell the words, such as "via8ria." Advanced filters use statistical analysis of spam based on word patterns and e-mail coding. Spammers began to bypass these filters, as well, which is why you might receive mail with subject lines as "It really works tdsxv." Spammers use the random text in the subject to throw off analysis.

Anti-spam filter

The new center filter analyzes every piece of mail received from the Internet for every employee and affiliate at Fred Hutchinson. The filter analyzes and scores each message in the e-mail header. Your e-mail application, such as Outlook or Mac Mail, usually conceals the header. So, until you set your option on the IT Web site or set your rules in your e-mail application, you will not notice a change in the amount of spam you receive.

Similar to a virus filter, PureMessage receives the latest information and updates for anti-spam techniques from the software manufacturer.

The filter does not resolve all issues with spam. New spam strategies may result in an increase of unsolicited e-mail until the filter receives an update. Furthermore, the filter can only identify obvious spam. Because it does not read the messages, it is possible that a graphic-rich notice about a scientific conference will be tagged as spam. However, in the great majority of cases, the filter will let in the ham and shut out the spam.

[Matt Briggs is a project coordinator in the Information Technology Department.]

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