What is a computer worm? How this self-spreading malware wreaks havoc

A worm is a form of malware (malicious software) that operates as a self-contained application and can transfer and copy itself from computer to computer. Worms generally target pre-existing vulnerabilities in the operating system of the computers they attempt to infect. Many of the most widespread and destructive forms of malware have been worms. The NotPetya worm, which rampaged across computer systems around the world in 2017, offers a good case study of how worms spread. The name worm is meant to indicate that a computer worm is higher than a virus.”]

Source: https://www.csoonline.com/article/3429569/what-is-a-computer-worm-how-this-self-spreading-malware-wreaks-havoc.html