Escalating Spam Wars Take Their Toll
Spam has never been cheaper. online-marketing firms are falling over themselves to offer spam campaigns of millions of addresses. These e-mail blasts are disturbingly inexpensive. Pro Software Pack, for example, charges just $125 to send 1 million mes sages. Despite spending billions of dollars fighting spam over the past decade, the security industry is in no danger of winning the war soon:
Spam now accounts for 19 of 20 e-mails, and its cost to businesses doubled between 2005 and 2007 to $100 billion (about a third of that in the United States), according to Ferris Re search, a San Francisco-based consultancy.
In their cat-and-mouse game with security, spammers have been innovative. To avoid filters, at first they inter changed some letters and numbers and broke up words with spaces. When keyword filters got better, spam appeared with addi tional, unsuspicious text that reduced the percent age of trigger words. Since the added verbiage confused recipients, spammers began sending it as invisible (white on white) text. When securi ty firms employed filters that could detect hidden text, spammers then be gan placing their mes sages on Web sites and providing links to them. When filters were pro grammed to hunt for spam by following links, spam e-mail appeared with dozens of links to legitimate Web sites to overwhelm filters. And so on.
