News Article - Chicago Tribune

E-mail filter launders out spammers' work

As part of his consulting business, Donald Drake provides Web hosting for some of his small-business clients, and he's been struck by how much unwanted electronic mail they get.

The Chicago-based consultant uses several open-source tools to sort out the spam, and he tweaks that software with some variations of his own. For one thing, he looks for uniform resource locators, or URLs, within e-mails intended to direct recipients to a Web site.

"Spammers are mostly trying to sell you something, and they usually have a URL embedded in their text to direct you to a site where they do business," Drake said. "My software looks for those and spots the known spammer sites."

Many spammers in Russia don't use Web sites, but they have phone numbers in their messages, Drake said, and his software looks for those phone numbers to spot spam. He also looks for URLs that direct people to bogus Web sites intended to look like the sites operated by legitimate banks and online merchants.

A major component of malevolent e-mail these days is a warning that customers of legitimate businesses need to go to a Web site and provide their Social Security and credit card numbers to assure the integrity of their accounts. The actual purpose of these "phishing" messages is to steal personal information that may be used later in fraudulent schemes.

Drake also incorporates antivirus software in his screening software, but he's found that computer viruses are a declining threat in e-mail, while phishing is on the rise.

After a year of building an effective spam filter for the Web sites he hosts, Drake decided to start promoting his filter, called MailLaunder.com, as a general service for small- and medium-size businesses.

"I've been promoting it for about a month," Drake said, "and have gotten clients in the Chicago area and Wisconsin. I also have a few clients outside the Midwest."

There are many spam filter services, and Drake said he hopes to compete through personalized service.

"I give clients my cell phone number," he said.

The persistent danger with filters is that they will label legitimate communications as spam, and Drake supplies his clients twice a day with an inventory of the communications his program has quarantined as spam.

"They can scan through it quickly and retrieve anything they want," he said. "Then they can alert us to white-list e-mail from those sources."

Drake charges roughly $1 per month per employee using e-mail that goes through his filtering service.

"The amount of spam varies from one client to another," he said. "In general, it's about 50 percent to 80 percent of total e-mail. In some cases, it exceeds 90 percent."