The Dangerous Side of Spam

Although seasoned network administrators may have grown accustomed to the nuisance of unsolicited e-mail, or spam, these messages may soon pose severe security threats, thanks to emerging software geared to give e-marketers more access to personal data.

Marketing companies have begun to embed invisible HTML "bugs" or "beacons" in their e-mail. Because these tiny one-pixel images must be retrieved from the sender's server when the message is opened, they can tell the sender when and how often a recipient looks at a message.

HTML makes browsers launch, and the senders can place cookies on every PC that accepts the e-mail message with a bug. As a result, those cookies allow the sender to gather information such as the recipient's IP address, the type of browser they use, and the Web sites they visit, according to experts.

While the tracking software may be a boon for the senders because they can gauge the effectiveness of online ad campaigns--perhaps using it to know exactly when to call a recipient at their desk--it could also be exploited to transmit viruses or as a tool for spammers to gain hundreds of corporate e-mail addresses, industry experts warn.

"It's just a matter of time [before] someone [can] figure out how to use these things against people or corporations," says Sharon Ward, director of enterprise business applications at Hurwitz Group.

Ward says that because the software requires a query to the sender's server, the bugs could be used to send e-mail viruses. "It could be a tricky little Trojan horse for getting viruses into unsuspecting people's e-mail."

Only two or three companies have developed this type of tracking software with a couple hundred marketers using it, Ward says.

In addition, spammers could use the bugs to get additional information about a company's e-mail addresses, says John Mozena, cofounder of the Coalition Against Unsolicited Commercial E-Mail.

"Because of the HTML bugs, you've confirmed to the sender that you've got the e-mail," Mozena says. "You've just made your address more valuable. It makes it more likely that your address will be sold or traded."

There are companies that specialize in blocking spam from entering the confines of a company's network. Brightmail offers a server-side solution that is designed to filter spam before it reaches mailboxes. Typically 30 percent of all corporate e-mail is spam, according to Ken Schneider, chief technology officer at San Francisco-based Brightmail. While network administrators may seek to stem some of the problem by blocking cookies in the browser, if the mail package is programmed to accept cookies, bugs could get to the user, he says.

Because the bugs allow marketers to confirm the validity of an e-mail address, they also may pose privacy concerns. Very few of the companies that use Web bugs detail how they use the software in their privacy polices, says Richard Smith, cofounder of The Privacy Foundation.

In addition to bugging e-mail, the software can also be used to track which sites a user visits on the Internet and to transmit information about a user, such as a zip code, from one Web site to another, Smith adds.

"It just says flat out that we're being tracked on the Internet," he says.