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 infects other computer systems that it comes into contact with by copying or inserting its code into the computer programs or software (executable files).

Some computer viruses that were popular in recent years are CryptoLocker, ILOVEYOU, MyDoom, Sasser and Netsky, Slammer, Stuxnet, etc.