PRESS RELEASE

COLUMBIA, Md., January 29, 2009 - Open source innovator and SNORT' creator, Sourcefire, Inc. (Nasdaq:FIRE), a leader in Enterprise Threat Management, today announced that its customers and Snort users have had zero-day protection from the rapidly spreading W32.Downadup/Conficker worm.

With reportedly more than 10 million systems currently infected, Conficker is on track to become one of the most widespread worms in history. The combination of Sourcefire's MS06-040 rules, released in 2006, its MS08-067 rules, released on October 23, 2008, and the company's generic shellcode detection rules delivered multiple layers of protection against Conficker, even before it was released in late November 2008.

The Sourcefire Vulnerability Research Team (VRT) leads the industry in providing same-day coverage for Microsoft Tuesday vulnerabilities, providing customers and Snort users with the confidence that their systems are protected. For more information about the Conficker worm and Sourcefire's protection, please visit the following VRT Blog posting: http://vrt-sourcefire.blogspot.com/2008/12/ms08-067-in-wild.html.

"Due to the speed with which the Conficker worm spread, anyone who waited for it to be discovered was probably too late," said Matt Watchinski, Senior Director of the Sourcefire Vulnerability Research Team. "This outbreak illustrates the need for organizations to take a proactive stance against security threats, not just protecting against known vulnerabilities and threats, but implementing solutions that can protect against even unknown threats. The Sourcefire Vulnerability Research Team works closely with our customers and the open source community to help ensure that they are safe from these types of attacks."

About the Sourcefire VRT The Sourcefire VRT is a group of leading edge intrusion detection and prevention experts working to proactively discover, assess and respond to the latest trends in hacking activities, intrusion attempts and vulnerabilities. This team is also supported by the vast resources of the open source Snort community, making it the largest group dedicated to advances in the network security industry.

About Sourcefire Sourcefire, Inc. (Nasdaq: FIRE), Snort creator and open source innovator, is a world leader in Enterprise Threat Management (ETM) solutions. Sourcefire is transforming the way Global 2000 organizations and government agencies manage and minimize network security risks with its 3D Approach - Discover, Determine, Defend - to securing real networks. This ETM approach equips customers with an efficient and effective layered security defense - protecting network assets before, during and after an attack. The names Sourcefire and founder Martin Roesch have grown synonymous with innovation and network security intelligence. For more information about Sourcefire, please visit http://www.sourcefire.com.

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