Rootkits

Rootkits are a type of malicious software designed to gain unauthorized root or administrative access to a computer or network. The term "rootkit" comes from "root," the traditional name for the privileged administrator account in Unix and Linux systems, and "kit," which refers to the software components that implement the tool.

Rootkits are designed to hide their existence or the existence of other software (such as viruses or spyware) on the computer. They can intercept and alter standard system calls, hide files, processes, and registry keys, and mask network connections and activities.

Rootkits often embed themselves deep within the operating system to intercept and modify system functions. Some operate at the kernel level, making them particularly hard to detect and remove. They provide persistent and undetected access to a computer system, allowing an attacker to remotely control the system and perform a range of malicious activities.

Due to their stealth and deep integration, rootkits can be challenging to detect with standard antivirus software. Removing a rootkit often requires specialized tools and techniques, and in some cases, the only reliable method is to completely reformat the infected system's hard drive.

There are many types of rootkits:

  1. Kernel-Mode Rootkits: Operate at the same security level as the operating system kernel, giving them significant control over the system.
  2. User-Mode Rootkits: Operate at the application layer and are easier to detect than kernel-mode rootkits, but they still offer significant control over user activities and system information.
  3. Bootloader Rootkits: Infect the system's bootloader and are executed before the operating system itself starts, making them extremely stealthy.
  4. Hardware or Firmware Rootkits: Reside in hardware firmware, making them very difficult to detect and remove.
  5. Memory Rootkits: Reside in the computer's RAM and are lost once the system is rebooted, but they can operate stealthily while the system is running.