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 …

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.

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 …

A computer virus is a malicious application or code used to perform destructive activity. Learn exactly what it is, how it works, examples, and more.

Oct 18, 2025 · A virus consists of a set of instructions that attaches itself to other computer programs, usually in the computer’s operating system, and becomes part of them.

Apr 28, 2022 · Computer virus definition A computer virus is a form of malicious software that piggybacks onto legitimate application code in order to spread and reproduce itself.

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 …

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 …

Dec 20, 2024 · What is a Virus? A computer virus is a malicious program, script, macro, or code designed to damage, steal personal information, modify data, send e-mail, display messages, …