Malware (malicious software) is a general term for software used to interfere with a computer, gather sensitive information, or gain access to a protected information system. This type of software is created and used by cybercriminals and other malicious actors, even governments, to intentionally harm an information system and/or steal information from it. In some cases, the goal of malware isn’t to harm a system but to scare the person using it.

Most malware consists of one or more files and behaves like a program or an app, but there is also malware that runs entirely in memory.

Malware can be classified by how it infects systems or by what it does on the system.