What is a Virus?
A computer virus is a program put on a computer without the owner’s permission and with some malicious purpose. The term ‘virus’ is used because of the way these programs are designed to copy or spread themselves from one computer to another, which is analogous to a biological virus. There are many different types of virus attack, some of them very similar to spyware. Sometimes the general term malware is used to refer to viruses and other malicious software.
Definition: “A parasitic program written intentionally to enter a computer without the users permission or knowledge. The word parasite is used because a virus attaches to files or boot sectors and replicates itself, thus continuing to spread. Though some virus’s do little but replicate others can cause serious damage or effect program and system performance. A virus should never be assumed harmless and left on a system.” -Symantec A functional definition of a computer virus must include the fact that it creates damage to the computer system “infected”; either inadvertently or deliberately. This definition is somewhat simplified and does not cover all virus types, but is sufficient to show the major differences between viruses and so-called “Trojan” programs, which is that the virus replicates, but the Trojan program does not. Many of us are computer users. (I bet you’re using one right now!) Whether we are systems analysts or just home users, the fact that we have access to computer t
A computer virus is a program – a piece of executable code – that has the unique ability to replicate. Like biological viruses, computer viruses can spread quickly and are often difficult to eradicate. They can attach themselves to just about any type of file and are spread as files that are copied and sent from individual to individual. In addition to replication, some computer viruses share another commonality: a damage routine that delivers the virus payload. While payloads may only display messages or images, they can also destroy files, reformat your hard drive, or cause other damage. If the virus does not contain a damage routine, it can cause trouble by consuming storage space and memory, and degrading the overall performance of your computer. Several years ago most viruses spread primarily via floppy disk, but the Internet has introduced new virus distribution mechanisms. With email now used as an essential business communication tool, viruses are spreading faster than ever. Vi
A virus is an application or hidden piece of programming code that is installed on a computer without the owner’s knowledge. Viruses usually cause unexpected, undesirable, or even destructive events to the receiver’s computer. Viruses can display messages, cause programs to act in unexpected ways, delete or alter files, change system or boot records in ways that require costly repairs, or even find sensitive information and send it back to the creator of the virus. The most common ways a virus can gain access to a computer are as an Email attachment, as a download, on removable media such as disks or through vulnerable services.
