Commtouch Reports August Spam Trends: Spammers Seek to Profit From Katrina; Using Katrina to Attract Recipients' Interest and Trick Anti-Spam Filters, Spammers Send 36% More Spam in August 2005 Than in August 2004.

MOUNTAIN VIEW, Calif. -- Commtouch(R) (Nasdaq:CTCH), the developer of ground breaking Recurrent Pattern Detection (RPD)(TM) technology for real time anti-spam and zero-hour virus protection, today announced spam trends and statistics for the month of August. The announcement was based on data from the Commtouch Spam Detection Center, which analyzed over 1.5 billion spam messages in the month of August 2005.

"Our analysis shows that spammers used Katrina to attract and hold recipients' interest. Typically, the subject of the email relates to hurricane related news, while the body of the message has nothing to do with the hurricane that devastated Louisiana," said Oren Drori, director of product marketing at Commtouch.

During a monitoring experiment of less than 5 hours, the Commtouch Spam Detection Center identified more than 250 examples of such spam outbreaks, with subject lines such as:

--"today's headlines: hurricane katrina slams into gulf coast; dozens are dead"

--"travelnewsletter - katrina affects cruise itineraries. stay safe!"

--"hurricane katrina update - nationwide storm survey"

--"Instantly track Katrina's progress john"

In other examples, variations on "Katrina" and "Hurricane" are used in multiple ways within the subjects of spam. The objective is to circumvent naive spam filters (such as Bayesian filters, which tend to white list messages by 'positive' keywords). Examples include:

--"Claim your stock car racing gift Katrina"

--"El 'Katrina' podria costarle a las aseguradoras mas de 20.000 millones"

--"Enter now for a complimentary trip to Maui Katrina"

--"Get an overnight $1500 cash advance for Katrina"

--"Katrina win a $50,000 scholarship"

--"Sexy hottie Katrina strips down"

Note: spelling and mistypes are from the original messages.

The Real Content: Drugs, Money and Sex

While some spam may have masqueraded as messages relating to Katrina, the true content of August 2005 remained similar to that of previous months. The list is headed once again by pharmaceuticals (29.15%), financing schemes (20.95%) and sex enhancers (14.19%).

Category          % of spam Popular subjects
----------------- --------- ------------------------------------------
Pharmaceutical    29.15%    "Cailis Softabs Onlly $3.99 d9Z"
Financing         20.95%    "Congrats on your Approval", "Get your
                             personalized rate quote NOW"
Sex enhancers     14.19%    "Alpha male", "Aging shouldn't mean the
                             end of your love life"
Software          10.42%    "Adobe Photoshop 8.0 - wholesale price",
                             "All software -- 75% OFF"
Porn & Dating     8.40%     "Date couples", "Dating for naughty
                             people"
Gifts & Shopping  8.40%     "Want a Rolex? Try a Replica First",
                             "Chanel, Dior, Louis Vuitton..."
Stocks & Frauds   3.28%     "The Next White Hot St0ck?" "Account
                             notification from eBay"
Other             5.21%

Spam Volume -- Significant Increase vs. Summer 2004

The Commtouch Spam Detection Center identified 27,664,737 new spam outbreaks in August 2005, averaging 922,158 outbreaks per day. This represents a slight decrease from July 2005, during which 33,977,674 spam outbreaks were detected. During the period July-August 2005, there were 36% more spam outbreaks than during the same period in 2004.

Spam Sending Domains

Spammers continue to abuse the reputation of the leading email service providers, forging messages so they appear to be sent from domains such as Yahoo, Hotmail and Gmail. The most popular domains used as "senders" in August 2005 were:

yahoo.com & yahoogroups.com     2.08%
hotmail.com                     1.35%
aol.com                         0.55%
gmail.com                       0.52%
msn.com                         0.30%
sympatico.ca                    0.26%
netscape.net                    0.25%
ebay.com                        0.22%
comcast.net                     0.22%
fusemail.com                    0.20%
ebay.de                         0.19%

About Commtouch

Commtouch Software Ltd. (Nasdaq:CTCH) is dedicated to protecting and preserving the integrity of the world's most important communications tool -- email. Commtouch has 14 years of experience developing messaging software, and is a global developer and provider of proprietary anti-spam and Zero-Hour virus protection solutions. Using core technologies including RPD Recurrent Pattern Detection, the Commtouch Detection Center analyzes 1.5 billion email messages per month to identify new spam and malware outbreaks within minutes of their introduction into the Internet. Integrated by 28 OEM partners, Commtouch technology protects thousands of organizations, with 35 million users in 100 countries. Commtouch is headquartered in Netanya, Israel, and has a subsidiary in Mountain View, CA. For more information, see: www.commtouch.com.

This press release contains forward-looking statements, including projections about our business, within the meaning of Section 27A of the Securities Act of 1933 and Section 21E of the Securities Exchange Act of 1934. For example, statements in the future tense, and statements including words such as "expect," "plan," "estimate," anticipate," or "believe" are forward-looking statements. These statements are based on information available to us at the time of the release; we assume no obligation to update any of them. The statements in this release are not guarantees of future performance and actual results could differ materially from our current expectations as a result of numerous factors, including business conditions and growth or deterioration in the Internet market, commerce and the general economy, both domestic as well as international; fewer than expected new-partner relationships; fewer than expected license agreements resulting from Commtouch's exclusive rights to market DCC; competitive factors including pricing pressures; technological developments, and products offered by competitors; the ability of our OEM partners to successfully penetrate markets with products integrated with Commtouch technology; a slower than expected acceptance rate for real time AV solutions in general and the Commtouch Zero Hour(TM) Virus Protection product in particular; availability of qualified staff for expansion; technological difficulties and resource constraints encountered in developing new products, such as the Zero Hour solution; and the failure of Commtouch to meet The NASDAQ SmallCap Market's listing standards in the future;, as well as those risks described in the text of this press release and the company's Annual Reports on Form 20-F and reports on Form 6-K, which are available through www.sec.gov.

Recurrent Pattern Detection, RPD and Zero-Hour are trademarks, and Commtouch is a registered trademark, of Commtouch Software Ltd. U.S. Patent No. 6,330,590 is owned by Commtouch.