A trojan horse is a piece of code or software that is designed to replicate itself and spread out from one computer system to another. Infections typically attach themselves to programs or files that are quickly transferred in between computer systems, such as email accessories or files downloaded from the internet. When a user opens a file or runs containing a virus, the virus code is executed and the infection begins to reproduce itself, often causing damage to the computer.

Bug can be categorized into 2 20 types of computer viruses (dailyuploads.net): worms and trojans. Worms are self-replicating and can spread themselves without the need for a host program or file. Trojans, on the other hand, do not reproduce themselves however can carry out malicious code on a computer.

Viruses can trigger a range of damage to a computer, ranging from deleting files to corrupting data. In many cases, different types of computer viruses (www.click4r.com) infections can contaminate a computer system without the user's knowledge, while in other cases, users might unknowingly spread out an infection and download by opening email attachments or clicking links in malicious sites.

There are a couple of ways to protect your computer from viruses. Avoid downloading pirated software or files from untrustworthy sites, as these are typically infected with viruses.