This unit introduced you to malicious software. It divided malicious software into two broad categories: parasitic software, which are subprograms or fragments of programs that require other system applications or utility software in order to run, and independent malware, which are self-contained programs that can run on their own.

Three key types of malicious software (viruses, worms, and distributed denial of service attacks) were then defined, along with the evolution of methods for handling them.

Part 1: Overview of Malicious Programs

Name and describe the five main categories of malicious software identified in Section 10.1 of the text. Provide an example of each that differs from the example provided in the text. Rank these categories from most dangerous to least dangerous, and provide a rationale for your ranking.

Part 2: Key Topics

Explain the fundamental differences between viruses, worms, and distributed denial of service attacks (DDoS).

Part 3: Countermeasures

Describe the countermeasures available to defend against viruses. How did these countermeasures evolve? Are the current countermeasures sufficient for handling existing virus threats? Why or why not?

Describe the countermeasures available to defend against worms. How do these compare to those available for viruses? How are countermeasure schemes combined to combat worms?

Describe the countermeasures available to defend against DDoS attacks. Are these countermeasures sufficient for handling existing attack methods? How do you believe they could evolve to provide greater protection?