Internet Security Systems Enhances Server Protection for Linux Platform; New Linux Product Increases Opportunity for ISS Channel Partners.

ATLANTA -- Internet Security Systems, Inc. (ISS) (NASDAQ: ISSX), the worldwide leader in preemptive, enterprise security, today announced Linux support for its Proventia(R) Server Intrusion Prevention System product line. Following on the heels of its Q4 2005 release of Proventia Server for Windows, this latest addition to ISS' product portfolio adds protection for the world's third-largest server market. According to IDC, Linux servers generated $1.6 billion in revenue in Q4 2005, the fourteenth consecutive quarter of double-digit growth, with year-over-year revenue growth of 20.8 percent.

"The extension of ISS' vulnerability-based protection to the Linux server market creates a powerful opportunity for channel partners," said Gary Fish, President and CEO of FishNet Security. "ISS' recent release of Proventia Server for Windows was well-received among our customer base, and we expect to see the same amount of enthusiasm for this new product. Designed as a set-and-forget security solution for an organization's entire population of servers (not just for dedicated servers running mission-critical applications), the Proventia Server for Windows and Linux products provide comprehensive protection that is both low-cost and easy to install and manage."

"With this additional support, ISS offers the most comprehensive coverage in the security industry for the top server platforms, including Windows, Linux, Solaris, HP-UX and AIX," said Heath Thompson, vice president of product engineering at Internet Security Systems. "Recognizing that the Linux market is growing rapidly and that many of our customers have heterogeneous environments, we also provide organizations the unique ability to manage security events for all of their servers using minimal resources through our Proventia Management SiteProtector(TM) console."

Key features of Proventia Server for Linux include vulnerability-based intrusion prevention, Buffer Overflow Exploit Prevention (BOEP) and support for Red Hat Enterprise Linux and SuSE Linux Enterprise Servers. ISS' vulnerability-based approach to intrusion prevention is based on the findings of the company's X-Force(R) research and development team. This proactive approach allows organizations to protect against software vulnerabilities before specific threats on those vulnerabilities emerge in the wild and impact network assets. By leveraging ISS' Virtual Patch(TM) technology, Proventia Server for Linux is constantly updated with vulnerability discoveries and can automatically patch and protect critical servers until organizations are able to obtain and apply patches from affected vendors.

Also key to ISS' preemptive server protection strategy is the company's BOEP technology, which protects hosts from attackers and worms that attempt to use known or previously unknown buffer overflow attacks to exploit the system or propagate. Server protection products and services from ISS combine intrusion prevention, enterprise firewalls and BOEP within a single agent to block a wide variety of Internet attacks from entering a system.

ISS' server offerings play a key role in the company's Proventia integrated security platform, which provides comprehensive protection for enterprise IT infrastructures from network to host. ISS' multi-layered approach to security allows organizations to continually stay ahead of the latest threats trying to infiltrate their networks.

Availability

Proventia Server for Linux is available now. For more information on ISS' various options for server security, please go to: http://www.iss.net/find_products/server.php.

About Internet Security Systems, Inc.

Internet Security Systems, Inc. (ISS) is the trusted security advisor to thousands of the world's leading businesses and governments, providing preemptive protection for networks, desktops and servers. An established leader in security since 1994, ISS' integrated security platform automatically protects against both known and unknown threats, keeping networks up and running and shielding customers from online attacks before they impact business assets. ISS products and services are based on the proactive security intelligence of its X-Force(R) research and development team - the unequivocal world authority in vulnerability and threat research. ISS' product line is also complemented by comprehensive Managed Security Services. For more information, visit the Internet Security Systems Web site at www.iss.net or call 800-776-2362.

Internet Security Systems, SiteProtector and Virtual Patch are trademarks and Proventia and X-Force are registered trademarks of Internet Security Systems, Inc. All other companies and products mentioned are trademarks and property of their respective owners.