Securing Cisco® Networks with Snort Rule Writing Best Practices (SSFRULES) is an instructor-led course offered by Cisco Learning Services High-Touch Delivery. It’s a lab-intensive course that introduces users of open source Snort or Sourcefire FireSIGHT1 systems to the Snort rules language and rule-writing best practices.

You will focus exclusively on the Snort rules language and rule writing. Starting from rule syntax and structure to advanced rule option usage, you will analyze exploit packet captures and put the rule writing theories learned to work by implementing rule language features to trigger alerts on the offending network traffic.

This course also provides instruction and lab exercises on how to detect certain types of attacks, such as buffer overflows, using various rule writing techniques. You will test your rule writing skills with two challenges: a theoretical challenge that tests your knowledge of rule syntax and usage, and a practical challenge in which you analyze and research an exploiting event, so you can defend your installations against attacks
This course combines lecture materials and hands-on labs throughout to make sure that you are able to successfully understand and implement open source rules.

Upon completing this course, the learner will be able to meet these overall objectives:

• Describe rule structure, rule syntax, rule options, and their usage
• Configure and create Snort rules
• Describe the rule optimization process to create efficient rules
• Describe preprocessors and how data is presented to the rule engine
• Create and implement functional regular expressions in Snort rules
• Design and apply rules using Byte_Jump, _Test, and _Extract rule options
• Describe the concepts behind protocol modeling to write rules that perform better

• Module 1: Welcome to the Cisco and Sourcefire Virtual Network
• Module 2: Basic Rule Syntax and Usage
• Module 3: Rule Optimization
• Module 4: Using Perl Compatible Regular Expressions (PCRE) in Rules
• Module 5: Using Byte_Jump, Byte_Test and Byte_Extract Rule Options
• Module 6: Protocol Modeling Concepts and Using Flowbits in Rule Writing
• Module 7: Case Sudies in Rule Writing and Packet Analysis
• Module 8: Rule Performance Monitoring
• Module 9: Rule Writing Practical Labs, Exercises, and Challenges

Lab Outline

• Lab 1: Infrastructure Familiarization
• Lab 2: Writing Custom Rules
• Lab 3: Drop Rules
• Lab 4: Replacing Content
• Lab 6: Optimizing Rules
• Lab 7: Using PCREtest to Test Regex Options
• Lab 8: Using PCREtest to Test Custom Regular Expressions
• Lab 9: Writing Rules That Contain PCRE
• Lab 10: Exploiting SADMIND Trust
• Lab 12: Detecting ZenWorks Directory Traversal Using Byte_Extract
• Lab 13: Writing a Flowbit Rule
• Lab 14: Extra Flowbits Challenge
• Lab 15: Strengthening Your Brute-Force Rule with Flowbits
• Lab 16: Research and Packet Analysis
• Lab 17: Revisiting the Kaminsky Vulnerability
• Lab 18: Configuring Rule Profiling
• Lab 19: Testing Rule Performance
• Lab 20: Configure Rule Profiling to View PCRE Performance
• Lab 21: Preventing User Access to a Restricted Site
• Lab 22: SQL Injection
• Lab 23: The SQL Attack Revisited

This course is designed for technical professionals who need to know how to write rules and understand open source Snort language. The primary audience for this course includes:

• Security administrators
• Security consultants
• Network administrators
• System engineers
• Technical support personnel
• Channel partners and resellers

The recommended knowledge and skills that a learner should have for the best learning outcome include:

• Technical understanding of TCP/IP networking and network architecture
• Working knowledge of how to use and operate Cisco and Sourcefire systems or open source Snort
• Working knowledge of command-line text editing tools, such as the vi editor
• Basic rule-writing experience is suggested