A computer virus is a software program deliberately designed to interfere with your computer’s operation. These programs can corrupt or delete your files, access your personal data, and will often use the Internet to spread to other computers.
Basic viruses rely on computer users to inadvertently share them. Some viruses, such as Trojans, can masquerade as beneficial programs in order to lure users into downloading and installing them. Other viruses, known as worms, replicate and automatically send themselves to other computers through software programs such as email.