Sunnyvale, Calif. – December 20, 2007 – Proofpoint, Inc., the leading provider of unified email security and data loss prevention solutions, today reported spam trends for data collected during the month of November 2007, finding that, on average, spam continues to represent nearly 90% 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% of total spam volume, up 23.79% over October.
• Microsoft Word document spam (.doc attachments) rose by 64.58% over October levels to 4.74% of total spam volume. Microsoft Word document spam in .rtf format also rose during November to represent 0.62% of total spam volume (a 264.71% 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% over October levels, representing 1.75% 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% of total spam volume, falling by 33.33%.

“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% effectiveness during the month of November.”

Spam Volumes Remain High During November

The Proofpoint Spam Index™ was at 88.17% in November, indicating once again that nearly 9 out of 10 email messages delivered to large enterprises were spam. The November index fell slightly from October’s index of 89.04%.

Learn More about Proofpoint’s Industry Leading Email Security and Data Loss Prevention Solutions

To learn more about Proofpoint’s email security and data loss prevention solutions, sign up to attend Proofpoint’s free, live Web seminar, “Top 10 Email Security Challenges – and Solutions – for 2008 and Beyond.” To register, please visit:

http://www.proofpoint.com/top10for2008

About the Proofpoint Spam Index

The Proofpoint Spam Index is a measure of the average amount of spam hitting the typical enterprise, university or government agency. The index is an average of actual spam volumes observed by Proofpoint systems deployed at a variety of customer sites, representing large organizations across a range of vertical industries including financial services, healthcare, higher education, manufacturing and business services. While spam volumes observed by individual organizations can vary widely, the Proofpoint Spam Index provides a useful baseline for monitoring general rises or declines in spam activity from month to month.

About Proofpoint, Inc.

Proofpoint provides unified email security and data loss prevention solutions for enterprises, universities, government organizations and ISPs to defend against inbound threats such as spam and viruses, prevent leaks of confidential and private information across all protocols, and encrypt sensitive emails. Proofpoint’s products are controlled by a single management and policy console and are powered by Proofpoint MLX™ technology, an advanced machine learning system developed by Proofpoint scientists and engineers. Proofpoint provides the most scalable and flexible deployment model including: hardware appliance, virtual appliance, hosted services and software. For more information, please visit http://www.proofpoint.com.

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Proofpoint, Proofpoint MLX and Proofpoint Spam Index are trademarks or registered trademarks of Proofpoint, Inc. All other trademarks contained herein are the property of their respective owners.