What is malware?
Malware is short for "malicious software." Malware is any kind of unwanted software that is installed without your adequate consent. Viruses, worms, and Trojan horses are examples of malicious software that are often grouped together and referred to as malware.
How to help protect your computer from malware
There are several free ways to help protect your computer against malware:
Warning: Cybercriminals sometimes try to trick you into downloading rogue (fake) security software that claims to protect you against malware. This rogue security software might ask you to pay for a fake product, install malware on your computer, or steal your personal information.
Don't click links in email messages and avoid websites that offer free software—especially free antivirus software. For more information, see Watch out for fake virus alerts.