What is it? Malware, or malicious software, is a blanket term for any kind of computer software with malicious intent (to be disruptive). Most online threats are some form of malware. Malware can take many forms, including viruses, worms, trojan horses, ransomware, and spyware.
There are 5 different categories of Malware
Timeline of Computer Viruses
5 Ways To Avoid/Prevent Computer Viruses