What is a computer virus? Name some computer viruses that were popular in recent years.
A computer virus is a piece of software code created to perform malicious activities and hamper resources of a computer system like CPU time, memory, personal files, or sensitive information. It mimics biological viruses by spreading on contact, infecting other systems by inserting its code into executable files. The virus remains dormant until the infected file is executed by the user.
Some well-known viruses include CryptoLocker, ILOVEYOU, MyDoom, Sasser, Netsky, Slammer, and Stuxnet. These viruses are often created with motives such as stealing passwords, corrupting files, spamming email contacts, or taking control of the user's machine.
Explanation
The answer is derived from section 12.2.1 of the textbook context. It defines a virus based on Fred Cohen's concept as malicious software that hampers system resources. The list of viruses (CryptoLocker, ILOVEYOU, MyDoom, etc.) is explicitly provided in the text under 'well-known viruses'. The explanation covers the behavior (dormancy, activation) and motives mentioned in the source.