Malware is malicious software designed to change your settings, delete software, cause errors, watch browsing habits, or open computer to attacks. It uses deceptive and unethical tactics to install itself on your computer without your consent. For instance, you may visit a website and receive an unrequested download, and mistakenly run this software on your computer. It may also use vulnerabilities in your operating system or web browser to install itself without requiring you to manually run the software.
Protecting a computer from malware
A computer can be infected by malware by visiting an infected website, downloading infected software, or installing infected software. Most antivirus programs can clean malware but it's also a good idea to run an anti-malware or malware cleaner such as Malwarebytes.