Hackers often break into computer systems or networks for the thrill or notoriety.
Spoofers break into computer systems as well by deceitful means. There are several different types of malicious code. Viruses, worms, and trojan horses are three of the most common. Virus is a program or piece of code that is loaded onto a computer surreptitiously to carry out either mischievous or destructive activities against your computer system. Worm is a type of virus or replicative code that propagates itself across computers, usually by creating copies of itself in each computer's memory.