The USA is back on top, at least when it comes to countries that relay spam email. That's the conclusion of the latest "Dirty Dozen" report of spam relaying countries. Although the majority of spam doesn't come from the United States, it does appear that, in the last three months, nearly one fifth (18.3%) of spam travelled through a system in the US. This is unlike the latter half of 2012 when India was top of the charts at 16.1%; now India has fallen to third position at 4.2%, behind China at 8.2%. Further behind the top three are Peru (4.0%), France, South Korea and Italy (all at 3.4%), Taiwan and Russia (both at 2.9%), Spain (2.8%), Germany (2.7%) and Iran (2.6%).

Aggregating the countries by continent though does offer a different view. While there has been a swing of 12% from Asia to North America, Asia maintains the top spot at 36.6% followed by Europe at 27.5%, North America at 22%, South America at 10.9% and Africa at 2.6%. Sophos believes this indicates only that spammers are finding it easier to compromise computer systems in the US.