An attacker can attempt to gain access to or exploit a system in many ways. This system can be as simple as a home computer connected to the Internet through a DSL connection, or a complex corporate network. Regardless of the kind of system an attacker targets, they typically employ the same fundamental steps:
The following sections discuss these steps in detail. You need to understand the concepts of what attackers might do in each step, and their goals, so you can detect and thwart their attacks.