Unlike biological viruses, computer viruses do not simply evolve by themselves computer viruses do not come into existence spontaneously, nor are they likely to be created by bugs in regular programs. They are deliberately created by programmers, or by people who use virus creation software. Computer viruses can only do what the programmers have programmed them to do.
Virus writers can have various reasons for creating and spreading malware. Viruses have been written as research projects, pranks, vandalism, to attack the products of specific companies, to distribute political messages, and financial gain from identify theft, spyware, and cryptoviral extortion. Some virus writers consider their creations to be works of art, and see virus writing as a creative hobby. Additionally, many virus writers oppose deliberately destructive payload routines. Some viruses were intended as “good viruses”. They spread improvements to the programs they infect, or delete other viruses. These viruses are, however, quite rare, still consume system resources, may accidentally damage systems they infect, and, on occasion, have become infected and acted as vectors for malicious viruses. A poorly written “good virus” can also inadvertently become a virus in and of itself (for example, such a ‘good virus’ may misidentify its target file and delete an innocent system file computer owner. Since self-replicating code causes many complications, it is questionable if a well-intentioned virus can ever solve a problem in a way that is superior to a regular program that does not replicate itself.
Releasing computer viruses (as well as worms) is a crime in most jurisdictions.
Effects of computers viruses
Some viruses are programmed to damage the computer by damaging programs, deleting files, or reformatting the hard disk. Others are not designed to do any damage, but simply replicate themselves and make their presence known by presenting text, video, or audio messages. Even these benign viruses can create problems for the computer user. They typically take up computer memory used by legitimate programs. As a result, they often cause erratic behavior and can result in system crashes. In addition, many viruses are bug-ridden, and these bugs may lead to system crashes and data loss.
