Answer:
Step-by-step explanation:
There is two main categories in malicious software.
1. worm
2. virus
A virus is a software program that can copy itself from one file to another to infect a computer. A computer worm is a software program that spreads from computer to computer through the network.
The primary difference between a virus and a worm is that viruses must be triggered by the activation of their host; whereas worms are stand-alone malicious programs that can self-replicate and propagate independently as soon as they have breached the system. Worms do not require activation—or any human intervention—to execute or spread their code.
Viruses are often attached or concealed in shared or downloaded files, both executable files—a program that runs script—and non-executable files such as a Word document or an image file. When the host file is accepted or loaded by a target system, the virus remains dormant until the infected host file is activated. Only after the host file is activated, can the virus run, executing malicious code and replicating to infect other files on your system.
In contrast, worms don't require the activation of their host file. Once a worm has entered your system, usually via a network connection or as a downloaded file, it can then run, self-replicate and propagate without a triggering event. A worm makes multiple copies of itself which then spread across the network or through an internet connection. These copies will infect any inadequately protected computers and servers that connect—via the network or internet—to the originally infected device. Because each subsequent copy of a worm repeats this process of self-replication, execution and propagation, worm-based infections spread rapidly across computer networks and the internet at large.