Any virus will by definition make unauthorised changes to a computer, which is undesirable even if no damage is done or intended.

Chances are you’ve heard how important it is to keep viruses out, but what is a computer virus exactly? A computer virus is a type of malicious software, or malware, that spreads between computers and …

May 22, 2025 · What Is a Computer Virus, Really? You’ve heard the term, but what does it actually mean? Learn from our expert how these self-replicating programs sneak in, spread, and slow your …

Oct 8, 2025 · A computer virus is a type of program that attaches itself to a host to multiply and spread to other computers. Here's a computer virus definition, examples of viruses, and more.

Jul 23, 2025 · What is a Computer Virus? A computer virus is a type of malicious software program ("malware") that, when executed, replicates itself by modifying other computer programs and …

Computer viruses spread across systems, infecting programs & files with malicious code. Learn to scan for viruses (and try our free virus scanner), remove viruses, and protect your computer against future …

Oct 18, 2025 · A virus is usually designed to execute when it is loaded into a computer’s memory. Upon execution, the virus instructs its host program to copy the viral code into, or “infect,” any number of …

A computer virus is an ill-natured software application or authored code that can attach itself to other programs, self-replicate, and spread itself onto other devices. When executed, a virus modifies other …

Mar 15, 2024 · What is a virus (computer virus)? A computer virus is a type of malware that attaches itself to a program or file. A virus can replicate and spread across an infected system and it often …

Mar 17, 2023 · What do viruses do? A virus is simply a computer program--it can do anything that any other program you run on your computer can do. Some viruses are designed to deliberately damage …