Lesson 1

Intruders are constantly trying to break into systems, snoop around, steal software, and corrupt programs. Intruders are not particular about their targets. Small systems are just as vulnerable as large ones when it comes to security. Once your system has been compromised, it can no longer be trusted, so you can save yourself time and money by being prepared.
This module discusses techniques to protect your system from unwanted intruders. By learning what intruders do when they break into your system, you will be able to better defend yourself against a break-in. You will also learn about known security problems and how to correct them. The techniques to determine whether or not your system has been compromised will also be discussed.

After completing this module, you should be able to:

1. Explain why it's important to protect your console
2. Describe security concerns related to network access
3. Explain how crackers get into a system
4. Describe what crackers do
5. List ways to detect attacks
6. Describe insecure remote login services
7. Describe secure remote login services
8. Control the root login process
9. Explain the use of the sudo command
10. Find modified and sticky files
11. Describe the cron facility
12. Describe RPM verification

In the next lesson, protecting your console access will be discussed..