How are bug produced?

Virus are produced by individuals who wish to trigger harm to others, or who wish to get control over somebody else's computer.  https://tastykoreachannel.com/?p=2429 The most basic way to create a virus is to take some existing code and customize it a little. This new code can then be dispersed to others, who may unsuspectingly run it on their own computer systems. Once the infection is running, it can do anything its developer desires it to, consisting of erasing files, stealing information, or sending out spam. More sophisticated infections can be very tough to spot and remove.