Three levels of crime:
unauthorised access to your computer
unauthorised modification of the computer without you knowing
unauthorised access in order to steal details or anything personal to misuse for purposes such as fraud and stolen identity.
Malware: software that damages the computer or disables the computer.
Trojan: is malware that appears friendly and then hacks the system of the computer and can steal data, also disabling the computer.
Spyware: self-installs and moniters your usage and gathers information about the person using the computer or system. e.g bank details.