According to a new study by Sophos, the US was responsible for 18.3% of all spam sent between December 2012 and February 2013.
China is ranked second in the list with 8.2% spam and India is ranked third with 4.2%.
Peru is ranked fourth with 4% of spam sent, while France, South Korea and Italy occupy the next places with 3.4%.
Taiwan and Russia were in the eight position with 2.9%, while Spain (2.8%), Germany (2.7%) and Iran (2.6%) were in tenth, eleventh and twelfth places respectively.
The study found that 41.1% of spam comes from the rest of the world.
In the top spam-relaying continents, Asia held the top spot with 36.6% followed by Europe with 27.5%, North America at 22%, South America at 10.9%, Africa at 2.6% and others at 0.4%.
SophosLabs said that this does not mean that the spammers themselves have migrated west – only that they’ve just recently had an easier time compromising computers in the US.
SophosLabs added that PC users should keep the anti-virus software updated and apply application security patches promptly in order to prevent spamming.
