According to operators of spam-filtering lists, an alarming number of people are unwittingly helping junk mailers shuttle spam, or unsolicited bulk e-mail. Those unassuming victims are running software meant to allow multiple connections over a LAN (local area network) to the Internet through a single line, or what"s known as proxy servers.
Many proxy servers are installed insecurely, and spammers have discovered tricks to tap into them to send junk mail with little trace--an occurrence relatively unseen a year ago, experts say. The problem has grown so quickly that some blocklist owners estimate that between 30 percent and 80 percent of the spam attacks today are caused by open proxies.
"Anybody on the planet can use (open proxies) to connect to mail servers if only you know how to talk to them," said Margie Arbon, director of operations for MAPS RealTime Blackhole List, a spam-filtering service that identifies IP (Internet Protocol) addresses that are the sources of spam. "The amount of spam going through them is scary," Arbon said.
With every spam blockade or filter erected, junk mailers dig new trenches to deliver billions of commercial messages to people every year. So far, they are winning the war. Some filtering companies expect spam will soon comprise the majority of message traffic on the Web.