Spam Mutates

Spammers are testing other waters, such as instant messaging and mobile phone text messaging, as well.

Judge estimates that 10 percent of instant messaging traffic is spam. "It is where e-mail traffic was several years ago," he says, adding that IM spam is likely to become even more ubiquitous as online messaging networks become interoperable (Microsoft and Yahoo, for example, have announced plans to allow their IM users to communicate with each other). The growing availability of IM services on cell phones will make instant messaging even more appealing to spammers--and vulnerable to viruses spread by spam, warns IMlogic, a messaging security firm.

Spammers have become increasingly attracted to cell phone text messaging. In fact, at least one case involving text messages has already made its way through the courts: This February, a federal court judge granted Verizon Wireless's request for an injunction barring Passport Holidays, a travel agency based in Ormond Beach, Florida, from sending unsolicited text messages to Verizon Wireless customers. In addition, Passport Holidays agreed to pay Verizon Wireless $10,000.

Verizon Wireless's lawsuit alleged that Passport sent 98,000 unsolicited messages to Verizon Wireless customers encouraging them to call a toll-free number to claim a cruise to the Bahamas.

But carriers aren't relying solely on the legal system to deal with the problem.

"We use filters and other tools to prevent spam from reaching our customers," explains Rochelle Cohen, a Cingular spokesperson.

Cingular also lets customers block incoming text messages at certain times of the day, and ban all incoming text messages that are sent via e-mail.

Wireless carriers say customers never see most spam because their spam-filtering software intercepts it. Verizon Wireless spokesperson Jeffrey Nelson says that the carrier works closely with conventional ISPs to learn the best ways to combat spam.

But while ISPs may be getting more effective at filtering traditional e-mail spam, junk e-mail marketing in general is getting ever uglier. "Filters make spamming harder, so spammers have to break the law to get a good delivery rate," acknowledges Amir Gans, the owner of New-Approach, an Israeli direct e-mail marketing company. Gans is identified by antispam nonprofit group SpamHaus as one of the top spammers--a label that Gans does not repudiate.

But while sending spam that can bypass filters (for example, by disguising a sales pitch to look like a personal e-mail) violates the U.S. Controlling the Assault of Non-Solicited Pornography and Marketing (CAN-SPAM) Act of 2003, many spammers shield their identity by using hijacked PCs--often referred to as spam zombies--to send spam (see our interview with a spammer).

Dan Larkin, head of the FBI's Internet Crime Complaint Center, says spam zombies are one of the agency's biggest challenges. And not only are more spammers employing the technique to increase spam volumes, but the e-mail itself has become more sinister and potentially more lucrative, Larkin says.

"Spam has grown from annoying to, in some cases, dangerous," he adds.