Internet Security Systems Proventia Desktop Positioned in Leaders Quadrant in Research Analyst Firm's Magic Quadrant Report.

ATLANTA -- Internet Security Systems (ISS) (NASDAQ: ISSX), the worldwide leader in preemptive, enterprise security, today announced that technology research firm, Gartner, Inc., has listed Proventia(R) Desktop Endpoint Security in the leaders quadrant in its Personal Firewall Magic Quadrant(1) for the first quarter of 2006. According to the Magic Quadrant report, personal firewalls will be an integral part of client computing by 2010.(2)

"We believe our positioning in Gartner's Personal Firewall Magic Quadrant demonstrates the industry's confidence in the market-differentiating preemptive approach that ISS takes to protect organizations from zero day threats and undefined viruses," said Greg Adams, vice president of product management at Internet Security Systems. "By trapping malicious behavior rather than relying on rules or signatures, Proventia Desktop protects customers from spyware and more than 97 percent of new and unknown viruses and worms without blocking healthy traffic."

Proventia Desktop, with its patent-pending ISS Virus Prevention System, automatically protects desktops and mobile devices against known and unknown threats by utilizing multi-layered security technologies. It includes a personal firewall that blocks unauthorized access not required for legitimate business needs. Proventia Desktop offers preemptive protection that works ahead of Internet threats to block attacks before they cause outages, employee downtime, excessive calls to the help desk or the compromise of critical information.

The ISS Proventia product line is a multi-layered security solution that provides comprehensive protection from network- and host-based attacks before they impact business assets, which is complemented by ISS Managed Security Services and Professional Security Services.

The Gartner Magic Quadrant is a graphical portrayal of vendor performance in a market segment, including categories for leaders, challengers, visionaries and niche players. It is organized based on companies' ability to execute in a space, as well as their completeness of vision in the market.

For additional information on ISS Proventia Desktop visit: http://iss.net/products/product_descriptions/Proventia_Desktop/index. html. (Due to its length, this URL may need to be copied/pasted into your Internet browser's address field. Remove the extra space if one exists.)

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, the 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. The ISS product line is complemented by comprehensive Managed Security Services and Professional Security Services. For more information, visit the Internet Security Systems Web site at www.iss.net or call 800-776-2362.

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

1 - The Magic Quadrant is copyrighted June 2006 by Gartner, Inc. and is reused with permission. The Magic Quadrant is a graphical representation of a marketplace at and for a specific time period. It depicts Gartner's analysis of how certain vendors measure against criteria for that marketplace, as defined by Gartner. Gartner does not endorse any vendor, product or service depicted in the Magic Quadrant, and does not advise technology users to select only those vendors placed in the "Leaders" quadrant. The Magic Quadrant is intended solely as a research tool, and is not meant to be a specific guide to action. Gartner disclaims all warranties, express or implied, with respect to this research, including any warranties of merchantability or fitness for a particular purpose.

2 - Gartner, Inc., Magic Quadrant for Personal Firewalls, 1Q06, John Girard, June 2006