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 …

Learn about computer viruses, how to scan (and try our free virus scanner), remove viruses, and protect your computer against future infections.

2025年10月8日 · 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.

What is a computer virus? 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 …

2026年1月2日 · A computer virus is a harmful program intentionally designed to access a computer without the owner’s permission, often with the goal of stealing or destroying data. Viruses typically …

2025年12月10日 · We’ve created an updated, chronological list of the most notorious computer viruses and malware incidents in history, from the early 2000s to the modern era. For each, you’ll find out …

2025年7月23日 · A computer virus is a type of malicious software program ("malware") that, when executed, replicates itself by modifying other computer programs and inserting its code. When this …

2026年1月8日 · Continue reading to learn about the most clear-cut warning signs of a virus or malware infection, how to check your computer safely, and what you can do to keep your devices safer.

2026年3月12日 · What Are Viruses, Malware, and Ransomware? We call these apps antivirus, but in truth, it's unlikely you'll encounter an actual computer virus.