Until now spammers have hidden the origin of their unsolicited e-mails by sending them through the computers of unsuspecting third parties.
Known as open proxies, or zombies, these remotely controlled computers are PCs infected with a virus that allows spammers anywhere in the world to secretly "bounce" or route e-mail through the servers of other organisations, thereby disguising the real origin of the e-mail.
ISPs and anti-spam sites such as Spamhaus have been able to filter out some of this spam, by blocking e-mail sent from computers identified as zombies.
However, according to reports, Steve Linford, the head of Spamhaus, warned earlier this week that a new virus had been developed that would instruct infected machines to send the spam through the mail server of the infected PC's own ISP, effectively sidestepping the existing blacklists.
Blacklisting affected ISPs is impractical, as the number of legitimate e-mails being sent through their systems is immense, and blocking those would disrupt the entire e-mail system.
"We've seen a surge in spam coming from major ISPs. Now all of the ISPs are having large amounts of spam going out from their mail servers," Linford told CNET News.com.
"The e-mail infrastructure is beginning to fail," he added. "You'll see huge delays in e-mail and servers collapsing. It's the beginning of the e-mail meltdown."
Separately, a study released yesterday from the Center for Excellence in Service at the University of Maryland's Robert H. Smith School of Business and research analysts Rockbridge Associates has found that the average person spends 2.8 minutes per day deleting spam.
This, says the 2004 National Technology Readiness Survey, costs the US economy around $21.6 billion per year.
The survey also found that 78% of the 1,000 adults surveyed received spam on a daily basis. Of these, 14% opened the spam to see what it said, and 4% purchased a product or service advertised by spam.
