Designed to spread from host to host and has the ability to replicate itself
In the same way that flu viruses cannot reproduce without a host cell
Computer viruses cannot reproduce and spread without programming such as a file or document
Computer virus
A type of malicious code or program written to alter the way a computer operates and is designed to spread from one computer to another
How a virus operates
1. Inserting or attaching itself to a legitimate program or document that supports macros in order to execute its code
2. Causing unexpected or damaging effects, such as harming the system software by corrupting or destroying data
Worm
A program that copies itself repeatedly, for example in memory or on a network, using up resources and possibly shutting down the computer or network
Trojan horse
A program that hides within or looks like legitimate program, and a certain condition or action usually triggers it
Rootkit
A program that hides in a computer and allows someone from a remote location to take full control of the computer. Once the rootkit is installed, the rootkit author can execute programs, change settings, monitor activity, and access files on the remote computer
