Worms are the most common form of malware. They are viruses that infect computers while replicating and spreading to others in the network.
Worms exploit vulnerabilities in devices’ operating systems, replicating and spreading until they burden the network by overloading servers with requests and monopolizing available bandwidth. Worms replicate without interaction with users, and they do not need to be attached to software programs in order to reproduce. A worm might be deployed on the Internet, and after scanning for machines running a prior Windows version lacking a security patch, it would infect the computer.
Some worms can carry payloads that damage host computers but often the burdens caused by self-replication are damaging and disruptive enough. Examples of well-known worms are the 1988 Morris worm, said to be the first known worm, as well as ILOVEYOU, Michelangelo, and MSBlast.
“Worms are the most common kind of malware and since these self-replicating virus attack OS vulnerabilities, a way to mitigate them is to update your OS to the most recent version since the security patches are a way of keeping a step ahead of these viruses.”