eSafe Anti-Spam Whitepaper

www.eAladdin.com


Anti-Spam White Paper
© 2003 Aladdin Knowledge Systems. All rights reserved 1-14
Table of Content

PREFACE.................................................................................................... 3 THE EMAIL SPAM PROBLEM ....................................................................... 3 LEGAL ISSUES............................................................................................ 4 HOW CAN SPAM BE STOPPED? ................................................................... 5 1. Real-time black lists...............................................................................................5 2. Internal Black lists and White lists.........................................................................6 3. DNS Lookup...........................................................................................................6 4. Anti-spoofing..........................................................................................................7 5. Header Analysis.....................................................................................................7 6. Mail-bombing prevention.......................................................................................7 7. Directory Harvesting Attacks Prevention ..............................................................7 8. Subject Analysis .....................................................................................................8 9. Spam Database ......................................................................................................8 10. Lexical Text Analysis ...........................................................................................9 11. Statistical (or Bayesian) text analysis ..................................................................9 12. Heuristic analysis.................................................................................................9 13. Porn Image Detection ........................................................................................10 14. Web-beacons, Cookies & Scripts .......................................................................10 15. OCR Text Recognition .......................................................................................10 16. Text Manipulation Analysis ...............................................................................10 17. URL Classification.............................................................................................11 18. Anti-relay ...........................................................................................................11 SPAM COLLECTORS: THE ESAFE SPAM ANALYSIS RESOURCE................. 11 QUESTIONS TO ASK AN ANTI-SPAM VENDOR ............................................. 12 DARE TO COMPARE ANTI-SPAM MATRIX................................................... 14

© 2003 Aladdin Knowledge Systems. All rights reserved 2-14 Preface The purpose of this document is to discuss issues and problems associated with spam email, describe available technologies to fight spam and explain how eSafe unique solutions can fight spam.
The Email Spam Problem Unsolicited commercial email, commonly referred to as spam, is growing rapidly and is finding its way to desktops both in the home and in the office. The major impact of spam is on ISPs that must cope with increasing amount of email traffic. Businesses are also suffering from spam attacks that affect their infrastructure and productivity. Spam is commonly compared to paper junk mail. However the difference is that junk mailers pay a fee to distribute their materials, whereas with spam the recipient or ISP pays in the form of additional bandwidth, disk space, server resources, and lost productivity. If spam continues to grow at the current rate, the spam problem may become unmanageable in the near future. The graph below (from bloodgate.com) shows spam statistics since 2000. We can clearly see an increase in spam emails since Q4/2000 and an exploding increase in 2003.
According to Jupiter Research, in 2001, U.S. consumers received over 140 billion 'spam' e-mails and since then the average amount of spam per user has increased from 3.7 to 6.2 emails per day. They predict that by 2007 spam email will ... [download for more]