The US continues to be the country responsible for most of the global spam, contributing 15 percent of the overall total says Sophos.

The security firm said that for the first time in two years, the UK has fallen out of the top 12 spam producing countries, which it nicknames the 'Dirty Dozen', to 14th place. Britain contributes just 2.1 percent of the world's spam.

Brazil has seen the biggest increase in spam production, jumping from fourth to second place since last year. The South American country is now responsible for 10.2 percent of global spam.

"The US has gone some way towards reducing levels of spam since last quarter, when the country relayed almost a fifth of all the spam messages," said Graham Cluley, senior technology consultant at Sophos.

"What's less encouraging is that Brazil has shot up the ranks. It's no secret that the country has long been associated with cybercrime - in particular the spread of banking Trojans. It's certainly a trend to keep a close eye on."

Sophos also revealed that 97 percent of all emails received by businesses worldwide is spam.

"Computer users should know by now that buying from spam is contributing to the problem, as well as putting their personal information into the hands of criminals - everyone should pledge to never ever buy via spam," added Cluely.