How do computer infections spread?

A virus is a kind of malicious code or program that, when executed, replicates itself by modifying other computer programs and inserting its own code. When this duplication is successful, the impacted areas are then stated to be infected with an infection.

Viruses often spread by producing a copy of themselves on a user's computer without the user's knowledge or approval. In a lot of cases, infections will be spread by e-mail accessories or by files shared on peer-to-peer networks.  https://catbitcoin.com/?p=1491 When a virus has infected a computer system, it can infect other computers on the exact same network.

read this Some infections are programmed to spread themselves in a method that could cause severe damage to a computer system. For instance, an infection may delete files, fill a hard disk with worthless information, or corrupt system files. In some cases, a virus may even show a message or image that is developed to scare the user.

The majority of viruses are fairly safe, and just cause minor inconvenience to the user. Some infections can be extremely unsafe, and can cause extensive damage to computer systems.