A computer worm, or worm for short, is a type of malware that reproduces itself independently. Unlike a virus, a worm is a piece of malware that acts independently, does not require a host file, and does not need a user to actively spread it. This has led to the near-complete replacement of computer viruses by worms.
Worms are often first introduced via phishing e-mails or instant messages containing malicious attachments. Disguised with double file extensions or harmless-looking file names such as “invoice”, they trick users into executing them. Once started, the worm enters the user’s computer in this way and begins to multiply independently.
To do this, it uses known security vulnerabilities in computers to multiply within a network, or it sends copies of itself to all contacts in the address book using an e-mail program. The primary goal is not to cause maximum damage, but rather to spread as far and wide as possible, which makes stopping a worm difficult.
First and foremost, worms slow down infected computers, rendering them temporarily unusable. A worm becomes more dangerous when it brings an attachment. This is called a payload. This could be ransomware, viruses or other malware that the worm smuggles into the system and that can cause serious damage.
