Global spam levels reached an all-time high of 95% of all e-mails at its peak during the third quarter, according to a new report by Commtouch.
The report, titled “Email Threats Trend Report for the third quarter of 2007,” found that as image spam declined, new kinds of attachment spam such as PDF and Excel spam increased. Pharmaceuticals and sexual enhancers were the most popular spam topics, at 30% and 23%, respectively.
The report found that there is a growing threat of innocent appearing messages, which contain links to malicious Web sites, and represented 8% of all global e-mail traffic during the peaks of various attacks during the quarter.
This type of spam uses zombie botnets, a consumer’s unknowing home computer, which has been infected, to send the spam. Some of these spam attacks focused on leisure-time activities, such as sports and video games. Messages invited consumers to download software such as NFL game tracking and video games from what appeared to be legitimate Web sites.
One outbreak mid-quarter used more than 11,000 dynamic zombie IP addresses to host malicious Web sites, with 36% of the zombies based in the US and 8% in Russia.
While botnets remain a big problem, image spam declined to a level of less than 5% of all spam, down from 30% in the first quarter of 2007. Image pump-and-dump spam, which pushes the buying and selling of cheap stocks has also fallen off.
PDF spam represented 10% to 15% of all spam in early July and then dropped significantly, however it is not gone entirely and still maintains 3% to 5% of all spam messages.
