Malware: Fighting Malicious Code

Worm Components

Now that we've seen some prominent examples of worms, let's delve inside to look at the guts of these beasts. Typical worms can be broken down into a common base set of components, which are illustrated in Figure 3.2. Think of each component in that figure as a building block used to implement a worm. Each of these building blocks has been found in the vast majority of worms we've witnessed to date. Additionally, attackers have created some worms that are highly modular, so various components can be more easily swapped as different functions are required. To get a feel for how worms are constructed, we'll step through the process worms use to spread and identify the purpose of various worm components at each stage of the infection ...