Proofpoint Reports Spam Email Trends for Nov. 2007
Wednesday, 02 January 2008
Proofpoint, Inc., a leading provider of unified email security and data loss prevention solutions, has reported spam trends for data collected during the month of November 2007, finding that, on average, spam continues to represent nearly 90 percent of the total email volume received by large enterprises. Attachment-based spam made a comeback with the prevalence of image-based spam, PDF spam and Microsoft Word document spam all increasing over October levels.
Attachment-based Spam Resurges
As Proofpoint has observed throughout the last part of 2007, spammers continued to change their spam distribution tactics in order to maximize delivery rates for their messages. Attachment-based spam — where the spammer’s message is included in a document attached to the email message itself — was up significantly in most categories:
Image-based spam continued to rise for the second consecutive month. During November 2007, image-based spam rose to 9.99 percent of total spam volume, up 23.79 percent over October.
Microsoft Word document spam (.doc attachments) rose by 64.58 percent over October levels to 4.74 percent of total spam volume. Microsoft Word document spam in .rtf format also rose during November to represent 0.62 percent of total spam volume (a 264.71 percent increase over October levels).
PDF spam, while still a very small percentage of total spam volume, rose to its highest levels since September. The use of PDF spam increased by 101.15 percent over October levels, representing 1.75 percent of total spam volume.
MP3 spam — where the spammer’s message is attached as an MP3 format audio file — continued to decline since its debut in October. During November, MP3 spam represented just 0.04 percent of total spam volume, falling by 33.33 percent.
“Because the mix of different spam types is constantly changing, enterprises need spam protection that automatically adapts to the latest threats,” said Rami Habal, director of product marketing for Proofpoint. “Proofpoint’s anti-spam solution, powered by Proofpoint MLX machine learning technology, has maintained extremely high effectiveness over the course of 2007, delivering an average of 99.87 percent effectiveness during the month of November.”
Spam Volumes Remain High During November
The Proofpoint Spam Index was at 88.17 percent in November, indicating once again that nearly nine out of 10 email messages delivered to large enterprises were spam. The November index fell slightly from October’s index of 89.04 percent.