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 …

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.

Feb 29, 2024 · What is a computer virus? Learn how computer viruses spread, how to spot them, and tips to keep them at bay.

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 …

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 …

A computer virus is an illegal, harmful, or malicious program that can change the way your computer runs and behaves. Some of these programs seek to cause as much damage as possible to the …

Jan 8, 2026 · 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.

Aug 31, 2022 · “Computer virus” is an umbrella term that describes many different types of malicious programs, which themselves use various delivery mechanisms and have diverse potential …

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.