The Email Wars

Zombie Networks Account for Majority of Spam in June
During June, spam sent through zombie PCs accounted for an average of 62 percent of all spam filtered by the MX Logic Threat Center. This compares with 55 percent in May and 44 percent in April.

“The continued proliferation of zombie PCs has levied a heavy cost on ISPs and email end users,” Chasin said. “Compromised PCs have resulted in millions of email users being unknowingly blacklisted, often through no fault of their own.”

Zombie PCs are neglected, “always-connected” broadband PCs that spammers hijack by installing a spam Trojan. Once infected, these zombie PCs provide worm authors with remote command-and-control spam-distribution capabilities, allowing them to create a legion of zombie computers that can pump out unwanted email and initiate Denial of Service (DoS) attacks.

“To make a real dent in the amount of spam sent globally, efforts must focus on helping service providers reduce outbound messaging abuse by identifying compromised PCs,” Chasin said.

One such effort began in May, when the Federal Trade Commission (FTC), along with 35 government partners from over 20 countries, unveiled “Operation Spam Zombies.” This international campaign is designed to educate Internet Service Providers (ISPs) and other Internet connectivity providers about hijacked, or zombie, computers that spammers use to flood inboxes.