Roughly three quarters of the world's email traffic was spam during December 2013, according to Russian security firm Kaspersky Lab.
Kaspersky Lab revealed the statistics in its Spam in December 2013 threat report, but reported that it expects spam levels to drop over the next month.
"The proportion of spam in global email traffic was up by 0.8 percent in December, reaching 73.3 percent. The amount of spam in circulation in January will probably be smaller, since early January is a quiet time for spammers," read the report.
During the period China, the US and South Korea were shown to be the worst offenders. China topped the list, as the source of 23.1 percent of the world's spam. Below it the US ranked second, with 19 percent of all spam. South Korea took third, with 13.9 percent of all spam. The UK did not make it onto the list of sources.
Interestingly, despite being third globally, South Korea was listed as being the source of 53.1 percent of spam targeting Europe. By comparison the US was only responsible for 7.4 percent of European spam. Britain was listed as being the source of just 0.8 percent of all European spam messages and failed to make it into the global list.
Kaspersky reported that its antivirus software detected the most malicious attachments in email in Great Britain, indicating that it is a high-priority target in Europe. Kaspersky said 14 percent of all malicious email attachments were detected in Great Britain. The statistic marks a 1.7 percent increase in Kaspersky antivirus detection levels recorded in November. The US took second place, with 13.2 percent of all antivirus detections.
The research highlighted a phishing campaign masquerading as a message from Samsung as being particularly prevalent in December.
"In December, we saw a large number of messages sent on behalf of Samsung. Emails sent on behalf of Samsung were supposedly written by one of the company's managers. In the messages, the ‘manager' wrote that he needed to arrange for certain goods to be supplied at short notice and that, after a long search for an intermediary, the recipient and his/her company was selected. The order for the goods to be supplied was included in the attached file," read the paper.
"In reality, the file attached to the message was a malicious program detected by Kaspersky Lab as Trojan-Spy.Win32.Zbot.qzpl. This is a Trojan spy from the Zbot/ZeuS family, designed to steal the user's confidential information."
Data-siphoning Trojan malware has been a growing problem facing businesses. Advanced threat mitigation experts at FireEye reported uncovering six new data-stealing malware variants targeting the Android platform on Tuesday.