In 2009, Brazil became the largest emitter of unwanted email (spam) in the world, surpassing the United States, reports the annual security report from Cisco Systems, released on Tuesday (8/12).

Brazil's participation in the volume of spam sent from servers located in the country rose from 2.7% in 2008, when the country was in second place in the ranking of spammers, to 7.7% this year, which shows an annual growth 192.6% according to the poll.

The United States dropped by 20.3% in the emission of unwanted messages over the last year and managed to reduce its participation in the global volume of spam from 8.3% to 6.6% in 2009.

"Emerging countries face a growing challenge to combat spam and should increase the resources to eliminate the spread of networks of botnets that generate fake emails or unproductive," says Cisco in its study.

Vietnam and India had the highest growth rates in the sending of spam this year. With a jump of 367.7% in the volume of spam sent in one year, Vietnam has occupied the sixth position in the ranking, representing 2.5% of global spam in 2009. India moved into third position in 2009, after presenting a growth of 130.4% in the spread of spam, accounting for 3.6% of the total volume of unwanted messages.

According to researchers from Cisco, the volume of spam sent from Brazil has nearly tripled between 2008 and 200. "The world's emerging economies account for 55% of global sending of spam," says Cisco.

Besides the United States, China, Russia and EU countries decreased the rate of spam sent this year. In the evaluation of Cisco, the efforts of Internet access providers to reduce reducing spam and botnets in developed economies are having an effect and should be shared with other countries.