What is a root kit?

A rootkit is a type of software designed specifically to grant unauthorized users remote control over a computer system. It allows the individual who deploys it to obtain complete and interactive access to the targeted device, often without the owner's knowledge. Rootkits are typically installed on a system to hide the existence of certain processes or programs from normal methods of detection while maintaining access for the attacker.

This capability is particularly concerning because the rootkit can mask other malicious activities and the presence of other types of malware. Often associated with privilege escalation, rootkits enable the attacker to operate with heightened permissions, effectively placing them in control of the entire system from a remote location.

The other options describe different types of software tools but do not align with the specific functionality and malicious intent that characterize rootkits. For example, the second option refers to adware, which displays advertisements, and the third option pertains to legitimate software that consentingly updates applications. The fourth option describes a worm, which spreads across networks but operates differently than how rootkits function, as worms do not typically involve remote control of a system.