Sophos has published its latest report on the top 12 spamming countries during the last six months.

Experts at SophosLabs analyzed all spam messages received in its global network of spam traps to identify the top 12 countries of origin for spam. The United States remains the worst offender, but is relaying significantly less of the world's spam than it did a year ago, while spam traffic from China and South Korea increased substantially.

Meanwhile, Sophos found that more than 60 percent of spam is now generated from zombie computers - hijacked PCs infected by malware. The evolving nature of spamming now allows culprits to be in a different country than the innocent computers they exploit.

26.35 percent of the spam relayed was from the United States, which is a huge drop from 41.50 percent recorded last year. South Korea went from 11.63 percent last year, to 19.73 percent this year. The spam coming from China (Hong Kong included) has almost doubled. The rate stood at 8.90 percent last year and is a whopping 15.70 percent this year. There was a rise in the amount of spam coming from France, Taiwan, Spain, UK, and Germany as compared to last year and a reduction in spam from Brazil, Canada and Japan. Sophos also recorded Pakistan as a "New Entry" with 1.42 percent with other countries accounting for the remaining 18.88 percent.

While the United States, South Korea and China still account for more than 50 percent of all spam, Sophos has seen a sharp drop in spam sent from North American computers due to a number of factors: jail sentences for spammers, tighter legislation, and better system security.

"Efforts such as ISPs sharing knowledge on how to crack down on spammers, and authorities enforcing CAN-SPAM legislation, have helped North America thwart the efforts of spammers on their doorsteps. Some of the most prolific spammers have been forced to either quit the business or relocate overseas as a result," said Graham Cluley, senior technology consultant for Sophos.

"The introduction of Windows XP SP2 a year ago, with its improved security, has also helped better defend home users from computer hijacking. The worry now is that devious spammers will turn to other net-based money-making schemes, such as spyware and identity theft malware to make their dirty money," said Clueley.

Feeling the impact of international awareness and country-specific legislation, spammers are increasingly turning to illegitimate providers to fuel their success and their key partners in crime are virus writers and hackers. By taking control of unprotected PCs, hackers can relay spam, launch denial-of-service attacks or steal user information, without computer owners being any-the-wiser.

"There are fortunes to be made from the dark side of the internet, and spammers who are finding it harder to sell goods via bulk email are likely to turn to other criminal activities," said Cluley.

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