Rootkit

A rootkit is a computer virus which allows someone to take control on your computer. It is very dangerous. 

It is a stealthy type of software, typically malicious, designed to hide the existence of certain processes or programs from normal methods of detection. It allows continued secret access to a computer.Rootkits, Part 1 of 3: The growing threat. McAfee 2006. 

Rootkits can be a single piece of code or multiple tools working together to affect the targets computer.

 References 

Category:Malware