A rootkit is a type of malicious software that is activated each time your
system boots up. Rootkits are difficult to detect because they are activated
before your system's Operating System has completely booted up. A rootkit often
allows the installation of hidden files, processes, hidden user accounts, and
more in the systems OS. Rootkits are able to intercept data from terminals,
network connections, and the keyboard.
eWeek News: UConn Finds Rootkit in Hacked Server The University of Connecticut has detected a rootkit on one of its servers, almost two years after the stealth program was placed there by malicious hackers.
Recognizing and Recovering from Rootkit Attacks Installing Rootkit is one of the more popular activities of serious Internet intruders once they have obtained root privileges of a workstation running SunOS 4.x Unix or the Slackware Linux distribution.