The report reveals that the top 12 spam-relaying countries for July to September 2010 are as follows:

1. United States 18.6%
2. India 7.6%
3. Brazil 5.7%
4. France 5.4%
5. UK 5.0%
6. Germany 3.4%
7. Russia 3.0%
8. S.Korea 3.0%
9. Vietnam 2.9%
10. Italy 2.8%
11. Romania 2.3%
12. Spain 1.8%

             Other 38.5%

This data shows that although the UK has dropped one position since the previous quarter, the spam-output from the United States has increased significantly from the second quarter of this year, rising from 15.2% to 18.6%.

The Sophos report identifies that the majority of this spam comes from malware-infected systems which are controlled by ‘botherder’ cybercriminals. This malware tricks computer users into clicking malicious links that direct computers to malware infected pages.

A rise in social networking spam during Q3 2010 is also noted by Sophos. The report specifically draws attention to the widely reported ‘onMouseOver’ exploit that creates spam tweets on Twitter and a bout of Facebook scams that have been created by spammers to generate money from survey websites.

Graham Cluley, Senior Technology Consultant, Sophos, comments: "What's interesting about the Facebook scams is that they exploit human weaknesses to spread – tricking users into filling in a questionnaire if they want to see a shocking picture or video that may not even exist. Unfortunately, these scams continue to proliferate, with new ones springing up every day, and Facebook seemingly unable to kill them off permanently."

On a more general note, the report shows that one in every 416 email messages between July and September contained a dangerous attachment. When compared to the previous quarter when the figure stood at only one in every 3333 emails, this is a staggering eight-fold rise.