The term rootkit is based on the Unix system where the root user is a super user of the system and has the most access and control of a system. Rootkit malware modifies the core kernal system files. It’s not running an application on the operating system. A root kit is effectively part of the operating system itself. Rootkits can be invisible to the operating system and may not be visible in Task Manager because it’s part of the operating system itself.
Rootkits can also bypass anti-virus software.
