Fake invoices still the most popular theme for distributing malware via email

Sep 1, 2009 09:29 GMT  ·  By

According to a report (PDF) from email and web security company MX Logic, pharmacy and other healthcare-related junk e-mails accounted for almost 69% of all spam last month. Meanwhile, malware authors preferred the fake invoice theme to distribute their creations via email.

The email and web filtering solutions vendor, which is in the process of being acquired by security giant McAfee, notes that spam volume has decreased by 2% compared to July. However, it warns that this number can be deceptive, because spam has actually increased by 0.3% compared to regular email, now accounting for 94.9% of all mail traffic.

"By far, healthcare remained the most prevalent category of spam in August despite decreasing slightly from the previous month," concluded the MX Logic analysts, who attribute this to the ongoing debate for reforming the Healthcare sector in US. The other notable categories were Offers (12.8%), Education (4.4%) and Gambling (1.3%), which appears to be on the rise.

Looking at the country of origin, the United States remains the biggest source of spam, being responsible for 13.3% of all junk emails. Brazil is very close behind with 13%, followed by India (5.6%), overtaking China in the top. In fact, spam of Chinese origin has dropped significantly, the country falling from third place in July to sixth in August.

The Bredolab trojan, which we recently wrote about, was the piece of malware most distributed via email during August. This finding is consistent with fake invoices being the preferred theme for infected emails during last month.

MX Logic predicts that social networking related spam will increase during September, partially due to the long standing but successful malicious eCards theme. "We are beginning to see some signs that eCards are making their way to popular social networking sites like Facebook or Twitter in the form of message or posting notifications," the company explains.

Cases of hacktivism related to the U.S. healthcare reform debate are also to be expected, the researchers say. Meanwhile, student campus networks might become the target of malware attacks, due to the poor protection that characterizes them.