Experts at SophosLabs scanned all spam messages received in the company's global network of spam traps and have revealed a dramatic rise in the proportion of the world's spam messages being sent from compromised Russian computers. The country has stormed into second place, accounting for 8.3 percent of the world's spam, or one in 12 junk mails seen in inboxes. Russia's rise is echoed in Sophos's research into which continents make the greatest contribution to the spam problem.

Between October and December 2007, the U.S. relayed far more spam than any other country, a testament to the sheer number of computers in the country that have been taken over by remote hackers. Representing the lion's share of total spam traffic, the United States' 21 percent slice means that more than one in five of all the world's spam emails was sent through compromised American computers.

The top 12 spam-relaying countries are as follows:

"Countries that continually remain among the top spam-relaying countries need to ensure that they are doing more to proper defend computer systems," said Mike Haro, senior security analyst at Sophos. "If they continue to sit back as compromised computers spread malicious emails and malware, then hackers will continue to look at these systems as easy targets in their efforts to turn them into botnets. ”

SPAM BY CONTINENT

Sophos's breakdown of spam relaying by continent is as follows:

Falling from first to third place, North America has managed to reduce the proportion of spam it is relaying from 32.3 percent to 26.5 percent and has been overtaken by Asia at the top of the chart and by Europe in second place.

MP3 PUMP-AND-DUMP SPAM

Using spam to artificially inflate the price of stock is an ongoing spam trend, but October 2007 saw one of the strangest schemes, when a pump-and-dump campaign used MP3 files in an attempt to manipulate share prices. In an effort to bypass spam filters, cybercriminals sent out their messages with supposed music files from stars such as Elvis Presley, Fergie and Carrie Underwood attached to the messages. The files actually contained a monotone voice encouraging people to buy shares in a little-known company.

"This spam campaign is a perfect example of how cybercriminals will change their approach and tactics in order to trick users into making bad choices," explained Haro. "Spammers will use any means to ensure that their messages reach their intended pool of victims."

For more information on 'Best practice advice for minimizing exposure to spam,' please visit: www.sophos.com/security/best-practice/