A virus is a type of malicious code or program that, when executed, duplicates itself by modifying other computer programs and placing its own code. When this replication prospers, the affected locations are then stated to be contaminated with an infection.
Infections frequently spread out by developing a copy of themselves on a user's computer without the user's knowledge or authorization. In most cases, infections will be spread by e-mail attachments or by files shared on peer-to-peer networks. Once an infection has infected a computer system, it can spread to other computers on the very same network.
Some viruses are programmed to spread themselves in such a way that could cause severe damage to a computer system. A virus might erase files, fill a difficult drive with useless data, or corrupt system files. Sometimes, an infection may even display a message or image that is designed to terrify the user.
Most infections are relatively safe, and only cause small inconvenience to the user. However, some viruses can be very hazardous, and can trigger prevalent damage to computer system systems. sites