SAN CARLOS--- Postini Reports Biggest Virus Outbreak Ever Processed; Sober Worm Still Spreading at Twice the Rate of Previous Re

Postini, the global leader in Integrated Message Management, within the last 24 hours of a massive virus outbreak, prevented more than 29 million copies of the Sober virus from reaching its worldwide customer base. Over the last seven days, Postini quarantined more than 218 million Sober-infected messages, making this outbreak twice as large as the largest previous attack on record.

"We typically quarantine about 50 million virus-infected emails in a month. This Sober virus generated close to a 1500% increase in virus-infected email traffic in the past week," said Scott Petry, founder and senior vice president of products and engineering at Postini. "Despite the virulence of the outbreak, our customers have not been affected by the Sober virus, and they experienced no message delivery latency issues or any degradation of service. We're blocking or quarantining all security threats before they reach our customers' networks."

This latest Sober worm arrives as a .zip file email attachment in either German or English, or in a message that appears to be from either the FBI or CIA. The Sober worm hijacks Windows-based computers, and forces them to send out continuous spam emails that overwhelm servers and reduce network performance. As with previous Sober variants, this worm can also disable antivirus programs. Though computers users are continually urged to use caution when opening attachments, many users opened the infected messages, enabling the Sober worm to spread rapidly.

Postini defended its customers against the attack through its multilayer anti-virus protection technology, which includes connection level threat analysis, heuristics-based content analysis, and anti-virus scanning engines from McAfee and Authentium. All Postini customers were fully protected and none were adversely affected by this Sober virus outbreak.

NOTE: Postini executives are available for further comment.

About Postini

Postini is the global leader in Integrated Message Management, providing compliance, security, availability, and visibility solutions for corporate email and instant messaging. Postini offers a complete suite of services including message archiving and discovery, spam and virus blocking, and messaging continuity. The company's powerful managed services infrastructure seamlessly integrates with customers' infrastructure, providing uncompromising security for more companies than any other provider in the world. Postini's services protect organizations from a wide range of threats, reduce compliance and legal risks, ensure reliable communications, and enable the intelligent management and enforcement of enterprise policies that protect companies' intellectual property, reputations and business relationships. No other company does more to reduce the cost, risks and complications of securing and managing IP-based messaging for businesses. For more information contact Postini at 866-767-8461, or visit http://www.postini.com/.