'Backscatter spam' gums up e-mail inboxes

USA TODAY, October, 2008 by Jon Swartz

SAN FRANCISCO -- E-mail users worldwide are being buried in a blizzard of bounced messages caused by spammers.

Dubbed "backscatter spam," this latest fad is clogging e-mail accounts and slowing victims' inboxes to a crawl. Up to 3% of all e-mail today is backscatter, says Dmitry Samosseiko, manager of SophosLabs Canada. "It is a major problem, and it is getting worse," he says.

How it works: Spammers collect real e-mail addresses, often through computer viruses that steal addresses from corporate databases. Then they fake -- or "spoof" -- those addresses to send spam that appears to come from an individual.

The trouble comes when spam sent from your spoofed address is aimed at e-mail addresses that don't actually exist. (Spammers often blast...