Rootkit

Rootkit is a type of malicious software explicitly designed to gain unauthorized access and control over a system while remaining hidden. A rootkit replaces or modifies critical system files, processes, or device drivers to enable unauthorized activities such as remote control, data theft, or malware installation. Owing to their stealthy nature, rootkits are notoriously hard to detect and remove while posing a severe danger to the integrity and security of the compromised systems.