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Hot Pick: Blue Coat ProxyAV 2000

Read this review of Blue Coat's AV appliance.

Blue Coat ProxyAV 2000
Blue Coat Systems
Price: Starts at $20,995

Headlines this summer declared that Internet Explorer is vulnerable to malware transparently downloaded from infected Web sites, and CERT recommended that enterprises consider less vulnerable browsers. Given this climate, it's no wonder that network-based antivirus solutions like Blue Coat's ProxyAV sound attractive.

The Blue Coat ProxyAV appliance provides inline protection against malware entering the network via Web-based e-mail, browser traffic, FTP downloads and malicious content or scripts.

ProxyAV works in tandem with Blue Coat's Proxy-SG caching appliance, which hands off Web content for inspection. Cleared content is cached by ProxySG for delivery to the requesting client, while malware is stripped or blocked based on admin-defined rules. ProxySG helps minimize latency by limiting scan requests to new objects. AV scan re-quests between ProxyAV and ProxySG are facilitated through the Internet Content Adaptation Protocol (ICAP).

Blue Coat's customization of ICAP means it can't support third-party proxy servers, which is why ProxySG, sold separately, is required. Blue Coat supports and resells McAfee, Sophos, Trend Micro and Panda, and requires an activation key for the resident AV product.

For testing, we placed a ProxySG 8000 between our Internet gateway and internal network. The scanning policy is configurable for individual users, groups, time of day, location, protocol, user agent, content type and other attributes. The ProxyAV works with traffic using HTTP, FTP, IM protocols (AOL, Yahoo and Microsoft) and several streaming media formats (Microsoft Media Server, Real RTSP and Apple QuickTime).

ProxyAV was adept at stripping out or stopping our virus samples. It blocked our virus-laden browser download and upload attempts, issuing warning messages and logging the incidents. Infected files were stripped from inbound transfers, and infected outbound FTP transfer attempts were consistently blocked, regardless of client type. The ProxyAV delivers on its promise of "scan once, deliver many," meaning that once an object is scanned and cleared, it's cached for delivery to all requesting clients.

ProxyAV's scanning added only minimal overhead--typically a few milliseconds--to normal Web traffic. Some particularly large files were too large to scan in a timely manner, triggering a customizable "be patient" message in the client's browser. Under certain circumstances, extremely large files can trigger errors or timeouts, effectively halting the download.

Blue Coat has already fixed several bugs that contribute to this problem.

A minor limitation is that the ProxyAV must be on the same subnet as the ProxySG and can't be separated by a router. The administration PC must also be on the same network segment.

Options for scanning files include setting timeout duration, dropping files if errors in scanning occur and defining trusted sites that require no scanning. Security managers can apply allow/deny lists using extension type, file size and content type restrictions. Customizable alerts notify security managers when a virus is found, if AV actions are successful and if files are dropped.

Blue Coat Systems' ProxyAV transparently scans Web-based mail and downloads for malware.

In rare instances, ProxyAV will allow files to pass without scanning. This usually only happens if the AV license has expired. Blue Coat is addressing this bug. Security managers are alerted to the unchecked file.

Reports track traffic requests -- connections attempted, successful, failed or cancelled -- along with numbers of files scanned and viruses caught.

The Blue Coat ProxyAV faces tough competition, including partner Trend Micro, whose VirusWall appliance tops out at 100 Mbps (though a gigabit model is on the way); ProxyAV has gigabit interfaces and claims HTTP throughput greater than 250 Mbps.

Despite the early-adopter bugs, the ProxyAV is worth serious consideration. Blue Coat made a smart choice by offering multiple vendors' AV engines, which complement its intelligent caching and aggressive performance.

About the author
Scott Sidel, CISSP, is a technical editor for
Information Security magazine. By day he leads a security team for Computer Sciences Corp. at the National Institute of Health.

This review orginally appeared in Information Security magazine.

This was last published in September 2004

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