Rootkit

A rootkit is a particularly insidious type of malware designed to hide its presence and the presence of other malicious software on a system. Rootkits modify the operating system itself to conceal malicious processes, files, and network connections from security tools and system administrators.

Rootkits are difficult to detect because they operate at a deep level within the operating system, often hiding from antivirus software and standard security tools. Detection typically requires specialized tools or analysis from a clean, trusted system. Some rootkits infect the boot process or firmware, surviving even operating system reinstallation.