BLUE COAT ADVISES SCANNING ALL WEB IMAGES FOR VIRUSES

Last Updated: November 30, 1999

SUNNYVALE, Calif., Sep. 21, 2004 -- Blue Coat™ Systems, Inc. (Nasdaq: BCSI), a leading provider of proxy appliances, today advised organizations to begin scanning all Web images for viruses at the Internet gateway. The recently discovered Microsoft Image Vulnerability -- which allows an attacker to execute malicious code when an infected JPEG file is executed -- has established a precedent that image files are now a vector for infecting the enterprise with malicious code.

According to research collected from Blue Coat's customer base, image files such as JPEGs and GIFs make up nearly 30% of all server-to-client Web traffic traversing the Internet gateway. While it has been safe for Web anti-virus solutions to ignore this 30% of traffic to allow better virus scanning performance, organizations must now include all image files in the anti-virus scanning process to ensure maximum network protection against future exploits. Scanning this additional volume of Web content requires a high-performance proxy-based Web anti-virus solution, such as Blue Coat's ProxyAV solution that scans Web traffic (HTTP, FTP) for viruses with up to 249 Mbps of throughput and only 4 milliseconds average latency, and supports popular anti-virus engines from leading vendors.

"This new vulnerability will force organizations to re-evaluate antivirus policy that allows anti-virus scanners to ignore image files, and possibly elevate the need for Web AV protection" said Peter Firstbrook, program director for META group. "Existing Web AV solutions are already taxed, and the increased workload from image files will make Web AV performance even more critical. Antivirus solutions should be anchored by the Web proxy in order to help satisfy performance requirements necessary for low latency Web traffic."

Blue Coat proxy appliances are designed to provide a secure filtering layer between users on an enterprise network and the Internet. Blue Coat's ProxyAV appliances work in concert with its market-leading ProxySG appliances to process and scan Web objects quickly and intelligently, leveraging integrated caching for optimal performance. Blue Coat offers protection against virus infected image files by scanning all Web images for viruses at the Internet gateway with very low latency. When an anti-virus signature does not exist for a new exploit, Blue Coat enables customers to defend themselves with rich policy controls (e.g. the capability to create a simple policy to remove or replace malicious object types from any "untrusted" Web sites.)

"This vulnerability dissolves the notion that image files can be ignored by anti-virus scanners," said Chris King, product marketing manager for Blue Coat. "The increasing number of attacks on the browser are requiring organizations to scan Web traffic for threats, while increasing threat vectors - like this image vulnerability - mean that organizations must build a Web AV infrastructure with high scalability and low latency - capable of scanning all Web traffic."

Blue Coat recommends referencing the white paper "Analyzing Web AV for Enterprise Deployment" located at www.bluecoat.com/resources/resourcedocs/whitepapers.html for more information. Those interested in learning more about the benefits of proxy-based anti-virus solutions should also visit http://www.bluecoat.com.

About Blue Coat Systems
Blue Coat enables organizations to keep "good" employees from doing "bad" things on the Internet. Blue Coat wire-speed proxy appliances provide visibility and control of Web communications to address today's new business risks - such as inappropriate Web surfing, viruses brought in via back door channels such as instant messaging and Web-based email, and network resource abuse due to peer-to-peer (P2P) file sharing and video streaming. Trusted by many of the world's most influential organizations, Blue Coat has shipped more than 18,000 proxy appliances. Blue Coat is headquartered in Sunnyvale, California, and can be reached at (408) 220-2200 or www.bluecoat.com.

FORWARD LOOKING STATEMENTS: The statements contained in this press release that are not purely historical are forward-looking statements, including statements regarding Blue Coat Systems' expectations, beliefs, intentions or strategies regarding the future, including the capabilities of the ProxySG and ProxyAV. All forward-looking statements included in this press release are based upon information available to Blue Coat Systems as of the date hereof, and Blue Coat Systems assumes no obligation to update any such forward-looking statements. Forward-looking statements involve risks and uncertainties, which could cause actual results to differ materially from those projected. These and other risks relating to Blue Coat Systems' business are set forth in Blue Coat Systems' most recently filed Form 10-Q for the quarter ended July 31, 2004, and other reports filed from time to time with the Securities and Exchange Commission.

Copyright (C) 2004, Blue Coat Systems, Inc. All trademarks, trade names or service marks used or mentioned herein belong to their respective owners.