A computer virus can be created maliciously by anyone who wants to damage systems or computers. They are hidden bits of code that attach themselves to other programs or applications and, when activated, spread like wildfire. Typically, viruses can be found attached to a document or software that is downloaded from the internet or shared via email. Most countries consider it illegal to create and propagate a computer virus.
In the world of computer viruses, there are a variety of kinds that can infect machines in different ways. Certain computer viruses are dependent on an application for starting their work. Others are independent and can attack multiple systems without a host. Computer viruses that utilize host programs to infect computers are usually known as worms but those that do not this link employ this method of infecting through other programs are known as viruses.
Some viruses can begin infecting systems as soon as they are discovered, while other remain dormant until the user unwittingly executes the code. The first computer virus was created in 1974 and behaved like a biological one by multiplying itself rapidly and causing harm to the system. One example of damaging viruses is the Stuxnet virus, which was specifically designed to destroy computerized centrifuges which were used to enrich uranium.
It is not for the weak-hearted to attempt this method. However, it can be an enjoyable and exciting way to test your knowledge of computer programming languages and systems. There are many resources that will show you how to create a virus, if you are willing and able to put into the effort.