Overall spam volumes averaged at slightly over 86 percent of all email messages in September 2009, which is a decrease of 4 percent since July 2009. However, it is considerably greater than September 2008 when spam levels averaged at 78 percent of all email.
Notable this month is that the percentage of spam containing malware has increased, reaching up to 4.5 percent of all spam at one point. When compared to August 2009, Symantec has observed a nine-fold increase in spam containing malware during September. With respect to spam categories, the main movers were Internet spam, which increased by 3 percent again this month and averaged at 32 percent of all spam; and financial spam, which decreased 3 percent to account for 17 percent of all spam.
Click here to download the October 2009 State of Spam Report, which highlights the following trends: