Aladdin Sees Dramatic Increase in Email Traffic with Outbreak of Win32.Sober.s

Proactive blocking of recent Sober variant sets Aladdin eSafe 2005 outbreak protection at 100 percent

CHICAGO, May 3, 2005 - Aladdin Knowledge Systems Ltd. (NASDAQ: ALDN today announced that its Content Security Response Team (CSRT) identifies the new Win32.Sober.s worm as a medium to high risk for corporate networks worldwide. Aladdin eSafe customers are proactively protected without a need for signature updates.

Win32.Sober.s is a mass-mailing worm that continues to quickly infect computers throughout the United States and Germany by disguising itself as a message from the FIFA soccer organization. With text in either English or German, it arrives as a .ZIP file containing a double-extension .EXE or .PIF file.

The Aladdin CSRT observes a total email increase of 30 percent as a result of a 400 percent increase in email viruses due to Win32.Sober.s. During the current Win32.Sober.s outbreak, viruses represent an average of up to 30 percent of all

incoming emails in organizations, mostly Win32.Sober.s. Spam amounts remain the same but its relative share falls to 60 percent while legitimate emails are just 9 percent. This is a dramatic increase in virus activity, with figures from a few days ago indicating that 65-70 percent of emails were spam, 10-15 percent were viruses, and 20-25 percent were legitimate email.

Aladdin eSafe, an integrated, proactive content security and anti-virus solution for gateways, consistently provides proactive protection while also handling significant, sudden increases in email traffic due to viruses. Aladdin eSafe proactively blocked all of the following 2005 virus outbreaks:

• January 25 -- Mydoom.am - Propagates via email and P2P networks
• February 17 -- Mydoom.bb.-- A simple variant that drops copies and moves on
• March 1 -- Bagle.be -- A variant of Bagle
• March 7 -- Serflog.a - An MSN Messenger virus - the first outbreak of its kind
• May 2 -- Sober.s - Widespread in the United States and Germany

For additional information on Win32.Sober.s or Aladdin eSafe, visit the Aladdin Content Security Response Team site at http://www.aladdin.com/csrt/index.asp.

Proactive Aladdin eSafe Protection

Aladdin's eSafe features high-performance, proactive content inspection that stops threats and increases employee productivity while reducing the load on corporate bandwidth. eSafe features the Proactive Security Engine (PSE). Using multiple technologies, the PSE enables eSafe to even block most zero-day malicious code. Performance is essential to content security - slow, inefficient solutions cannot be tolerated in today's fast-paced networks. eSafe's NitroInspection™ provides a high-speed solution that efficiently combines operation of all core technologies at the gateway to the organization. The Aladdin eSafe product suite includes eSafe Gateway, eSafe Mail and eSafe Appliance. For more information on eSafe, and the entire family of eSafe content security and anti-spam solutions, visit http://www.Aladdin.com/eSafe/default.asp.

About Aladdin Knowledge Systems

Aladdin (NASDAQ: ALDN) is a global provider of software digital rights management (DRM) and enterprise security. Aladdin products include: the HASP® family of hardware and software-based products that flexibly protect, license and distribute software and intellectual property; the USB-based eToken™ device for strong user authentication and e-commerce security; and the eSafe® line of integrated content security solutions that protect networks against malicious, inappropriate and nonproductive Internet-borne content. Visit the Aladdin Web site at http://www.Aladdin.com.

####

All trademarks and registered trademarks are the property of their respective holders.