Spam's dirty dozen: Sophos

The US, South Korea and China are among the top 12 countries for originating spam, according to a report.

Other countries listed in the top 12 were Brazil, Canada, Japan, Germany, France, Spain, the UK, Mexico and Taiwan.

The report, published by software vendor Sophos, looked at the countries from which the most spam messages originate.

Sean Richmond, technical support manager at Sophos Australia and New Zealand, said that the US had retained its position as the highest originator of spam.

Australia doesn't feature in Sophos' top 12 list. Richmond said the amount of spam coming from Australia had almost halved since February, compared to the rest of the world.

"With increased awareness of anti-spam techniques resulting in fewer available open relays and recent legislation, spammers may have been encouraged to move their operations offshore," he said.

In contrast, the amount of spam originating from South Korea has almost tripled since February.

Richmond said that research had shown up to 40 percent of all spam is generated by broadband connected PCs that had been compromised by hackers or virus writers. "Up-to-date anti-virus software is a significant barrier against the spread of malicious code used to hijack innocent users' computers," he said.

According to the statement from Sophos, researchers had scanned all spam messages received at its global network of honeypots in the last month to figure out the top 12 spam-producing countries.