rootkit

A rootkit is a set of software tools frequently used by a third party (usually an intruder) after gaining access to a computer system. These tools are intended to conceal running processes, files or system data, which helps an intruder maintain access to a system without the user's knowledge. Rootkits are known to exist for a variety of operating systems such as Linux, Solaris and versions of Microsoft Windows. The rootkit concept is the dominant controversial aspect of the 2005 Sony CD copy protection controversy, which has made the previously obscure concept of a rootkit much more widely known in the technology community, and to the general public