Chapter 10. Understanding Your PC Operating System and Its Security Features

An essential step in protecting and defending your privacy in the online environment is understanding the security features that are available via the computer's operating system. Having a secure system will help prevent successful attacks against your system. The operating systems and computers we will be discussing all contain basic security features, but it is often left to the consumer to configure and enable those features. Although this book and its recommendations are geared toward the home user, many of the security issues we will discuss can also be applied in the office environment, subject to your company's security policies. For example, policies that govern the use of encryption in your organization might already be in place. Obviously, those procedures should be followed first. Good security habits followed in the work environment should be carried over to your personal home computers.

This chapter focuses on Windows 95/98, Windows NT, Windows 2000, and general Unix (Linux) security, but these same principles can be applied to all types of operating systems.

How do attackers select and gain knowledge about your computer or network? In the case of the casual home user, the selection of a victim system is more likely by chance. Attackers can easily identify networks and their ownership by performing the address and domain lookups described in Chapter 6, “Understanding the Online Environment: Addresses, Domains, and Anonymity.” For example, large providers of cable modem and DSL services such as Road Runner, Mindspring, and AOL have IP network address blocks that someone can look up. This makes it easy for the attacker to specifically target the home user's machine. Using the same methods, the attacker can also target other entities, such as ISPs that cater to small businesses. After an attacker has identified your presence on the Internet (your IP address), the process known as footprinting begins.