Worm

Worm, in computing, is a type of malicious software that spreads by copying itself to other computers. It generally does not modify files or programs and does not delete or otherwise damage data, though some variants are known to corrupt or destroy files or programs. Worms are often seen in the context of network security and cyberattacks.

Worms have their origins in the 1980s, when Robert Morris released the first known example of a self-replicating program. The Morris worm exploited vulnerabilities in Unix-related software to spread itself throughout the ARPANET. After some contemporary publications discussed the worm, others began to create similar programs of their own.

While the original Morris worm was not malicious, some worms are designed deliberately to cause damage or disruption to computer networks. These malicious worms may be used to steal information, install other types of malicious software, or use the infected machines to commit additional cyberattacks.

Worms differ from other forms of malware in that they do not require a user to take any action; they can spread by themselves, merely by exploiting known vulnerabilities. This makes worms very difficult to stop once they have been released into the wild.

The primary defense against worms is keeping software and operating systems up to date. Security patches should be applied as soon as they become available. In addition, security products such as firewalls and antivirus/anti-malware software are important tools to protect systems from worms.