正解:C,D
The term 'rootkit' originally comes from the Unix world, where the word 'root' is used to describe a user with the highest possible level of access privileges, similar to an 'Administrator' in Windows. The word 'kit' refers to the software that grants root-level access to the machine. Put the two together and you get 'rootkit', a program that gives someone - with legitimate or malicious intentions - privileged access to a computer.
There are four main types of rootkits: Kernel rootkits, User mode rootkits, Bootloader rootkits, Memory rootkits