How are computer infections developed?

Trojan horse are produced by individuals who wish to trigger damage to others, or who want to acquire control over another person's computer system.  https://catbitcoin.com/?p=821 The most basic way to produce an infection is to take some existing code and customize it a little.  official website This new code can then be distributed to others, who may unknowingly run it by themselves computer systems. Once the virus is running, it can do anything its developer desires it to, including deleting files, stealing information, or sending out spam.  Full Article More advanced infections can be extremely tough to get rid of and find.