The Network Security Test Lab: A Step-by-Step Guide

CHAPTER 9 An Introduction to Malware

This chapter discusses malware, not just from a historical perspective, but also with an up-to-date review. Malware has changed over the years, and started as something much more basic than it is today. One consistent thing about malware is that it is a threat that is constantly changing. Years ago, malware consisted of viruses and worms. Today, malware includes rootkits, spyware, ransomware, and even crimeware kits. These different kinds of malware will be examined in this chapter. Each has the potential to damage company networks as well as home computers. This chapter also looks at the methods used to detect, eradicate, and prevent such threats. Many of these defenses can be tested in your network security lab.

History of Malware

The best way to understand and deal with the threat of malware is to explore its background and learn how we got to where we are today. Malware did not really exist until 1984, when Fred Cohen coined the term computer virus. He was working on his doctoral thesis and needed a term to describe replicating programs. An advisor suggested that he call such code computer viruses.

Worms appeared shortly thereafter. The first known computer worm, the Morris worm, was not released until 1988. Since then, malware has grown, changed, and become a much bigger threat. For many years, the motivating factors behind the development of malware were fame and notoriety. Consider the 1986 Brain virus, which was developed by two ...