Today I’m going to talk about: Computer virus I’ve divided my presentation into two parts: First I’d like to introduce of this virus and second I’ll presenttypes of virus. So, let’s start with introduce Virus (computer), self-duplicating computer program that interfereswith a computer’s hardware or operating system. Viruses are designed toduplicate or replicate themselves and to avoid detection. Like any othercomputer program, a virus must be executed for it to function, it must belocated in the computer’s memory, and the computer must then follow thevirus’s instructions. These instructions are called the payload of thevirus. The payload may disrupt or change data files, display an irrelevantor unwanted message, or cause the operating system to malfunction.Computerviruses activate when the run programs are opened. Once a virus is active,it may replicate by various means and tries to infect the computer’s filesor the operating system. For example, it may copy parts of itself to floppydisks, to the computer’s hard drive, into legitimate computer programs, orit may attach itself to e-mail messages and spread across computer networksby infecting other shared drives.