rootkit

[ root-kit, roo t‐ ]
/ ˈrutˌkɪt, ˈrʊt‐ /
Computers.

noun

malicious software that allows an unauthorized user to maintain access to a computer by concealing programs and processes, files, or data from the operating system.

verb (used with or without object), root·kit·ted, root·kit·ting.

to install such software on (a computer, electronic device, etc.): I think my system has been rootkitted.

Origin of rootkit

root1 (conventional name for the username or account of a UNIX administrator) + kit1

British Dictionary definitions for rootkit

rootkit
/ (ˈruːtˌkɪt) /

noun

computing a set of programs used to gain unauthorized access to a computer's operating system, esp in order to destroy or alter files, attack other computers, etc