Comcast"s high-speed Internet subscribers have long been rumored to be an unusually persistent source of junk e-mail.
Now someone from Comcast is confirming it. "We"re the biggest spammer on the Internet," network engineer Sean Lutner said at a meeting of an antispam working group in Washington, D.C., last week. Lutner said Comcast users send out about 800 million messages a day, but a mere 100 million flow through the company"s official servers. Almost all of the remaining 700 million represent spam erupting from so-called zombie computers--a breathtaking figure that adds up to six or seven spam-o-grams for each American family every day.
Zombie computers arise when spammers seize on bugs in Microsoft Windows--or from naive users who click on attachments--to take over PCs and transform them into spambots. No hard numbers exist, but some estimates say that about one-third of spam comes from zombie computers with broadband connections. The owners of the zombie PCs typically don"t even notice what"s happening. Because home computers are more likely to be infected than business PCs, and because Comcast has about 6 million high-speed customers, it may have been inevitable that the cable provider became a haven for remote-controlled zombies that churn out junk e-mail.