Asia is now considered the top continent in the world for relaying over 50 percent of spam throughout the world, according to the latest research by Sophos, an IT security and data protection company.

For its third quarter report, Sophos also noted that five countries in the region have joined the rest of the so-called "Dirty Dozen" list of the top countries that are sources of global spam.

The US remains the top source of spam with 11.3 percent of spam coming from them. But South Korea is now a second with 9.6 percent. Sophos said South Korea jumped up the list five places compared to where it was during the same period last year.

Asia contributes 50.1%

Joining South Korea in the top 12 are India (as a source of 8.8 percent of spam worldwide), Taiwan (at 3.8 percent), Vietnam (3.5 percent) and Indonesia (3.3 percent). India dropped to third place.

Together with the other countries in the continent, Asia was responsible for 50.1 percent of spam released to e-mails worldwide during the period in review compared to only 35.1 percent at the beginning of 2011.

"The spam that attempts to smash its way into users' e-mail accounts can vary from being annoying adverts to downright malicious attacks. In the worst cases, a spam message might be designed to infect your computer with a Trojan horse or phish your banking credentials," said Graham Cluley, senior technology consultant, Sophos. "These latest statistics suggest that, as more people get online in Asia, they are not taking the right measures to protect their computers from infection, which results in the growth of botnets."

Majority of spam from botnets

Sophos said the majority of spam emails are distributed by botnets - networks of infected machines, called zombie computers, which are under the control of spammers. Botnets are also used to launch Distributed Denial of Service attacks (DDoS), where thousands of zombie computers are used to connect to a website, forcing it offline as it struggles to cope with the increase in traffic.

Computers risk being victimised by botnets if these computers don't run up-to-date antivirus software and security patches, said Sophos.

"If you receive spam messages, check any filter settings you may have and make sure your security software is running and has the latest patches installed," said Cluley. "Don't ever be tempted to buy anything via spam, as that's what makes it worthwhile for the spammers. Don't even open unsolicited e-mails as that alone could lead to malware infection - send them straight to the trash."