Researchers at U.K.-based security vendor Sophos identified the top 12 spam-relaying countries in its "Dirty Dozen" report that analyzed spam volume between April and June of 2013. The analysis determined the extent to which computers in a given country are used for delivering spam.
Sophos said three new countries entered the top 12 while several other countries -- France, Peru and South Korea -- fell off the list. Spam volume in countries sometimes mirrors population, according to Sophos.
Spam messages, which are often viewed as unwanted messages pitching pharmaceuticals and pornography, also pose a serious threat. Sophos said. The unwanted messages can include phishing schemes and malware, and spammers have been seen pushing investment scams and other fraudulent activities, Sophos said.