In today’s constantly connected world you can contract a computer virus in many ways, some more obvious than others.
While some viruses can be playful in intent and effect, others can have profound and damaging effects, such as erasing data or causing permanent damage to your hard disk, and worst yet, some are even design with financial gains in mind. Stealing passwords or data, logging keystrokes, corrupting files, spamming your email contacts, and even taking over your machine are just some of the devastating and irritating things a virus can do. However, once the virus infects your computer, the virus can infect other computers on the same network. This means that a virus can remain dormant on your computer, without showing major sings or symptoms.
In order for a virus to infect your computer, you have to run the infected program, which in turn causes the virus code to be executed. Once a virus has successfully attached to a program, file, or document, the virus will lie dormant until circumstances cause the computer or device to execute its code.
In the process a virus has the potential to cause unexpected or damaging effects, such as harming the system software by corrupting or destroying data. A virus operates by inserting or attaching itself to a legitimate program or document that supports macros in order to execute its code. In more technical terms, a computer virus is a type of malicious code or program written to alter the way a computer operates and that is designed to spread from one computer to another. Similarly, in the same way that viruses cannot reproduce without a host cell, computer viruses cannot reproduce and spread without programming such as a file or document.
A computer virus, much like a flu virus, is designed to spread from host to host and has the ability to replicate itself.