A Rootkit is a type of security threat that can persist across system reboots, making it difficult to detect and remove. Rootkits operate by embedding themselves deep within the operating system, often at the kernel level, and they can disguise their presence by intercepting and modifying standard operating system functionality. Here's how they maintain persistence:

Kernel-Level Integration: Rootkits modify core operating system files, allowing them to load during the boot process and remain active after reboots.

Stealth Techniques: By hiding from regular security checks, rootkits avoid detection by conventional anti-virus and anti-malware tools.

Persistence Mechanism: The modifications rootkits make ensure they start up again after each reboot, enabling continuous threat activity on the compromised system.

Due to their persistence and stealth, rootkits present significant challenges for endpoint security.