Defend I.T.: Security by Example

Chapter 6. Virus Outbreak II: The Worm

In Chapter 5 we discussed the case of a virus and the potential harmful effects that a virus can have on the availability of IT resources and the overall productivity of a firm. Virus incidents can certainly be harmful events. Potentially even more deadly than a virus, however, is a worm, especially the polymorphic worm that we will discuss in this chapter.

Viruses and worms are often thought of as one and the same thing; they can certainly be considered to belong to the same family. In layman’s terms, a worm is a virus on steroids. A polymorphic worm is one that can change itself after each infection so that its signature is slightly different on each infected host. This ability to change signature makes ...