Which rootkit type is described as substituting or injecting code into the kernel to conceal attacker activity?

Which rootkit type is described as substituting or injecting code into the kernel to conceal attacker activity?

• A. Hypervisor Level Rootkit
• B. Library Level Rootkits
• C. Kernel Level Rootkit
• D. Hardware/Firmware Rootkit

Answer: (C)

A kernel-level rootkit is designed to operate inside the core of the operating system. By substituting or injecting code into the kernel, it gains full control over how the system enforces its basic operations. This allows it to tamper with kernel data structures and hook kernel routines, so it can hide its own processes, files, network connections, and other artifacts from normal security tools and user-space investigators. The depth of access and the ability to alter fundamental OS behavior make this type the most effective at concealing attacker activity. In contrast, library-level rootkits patch user-space libraries to influence how programs run, but they don’t modify the kernel itself. Hypervisor-level rootkits reside in a virtualization layer above the OS, controlling the guest from outside the kernel. Hardware/firmware rootkits hide within the hardware or its firmware, independent of the OS kernel.

A kernel-level rootkit is designed to operate inside the core of the operating system. By substituting or injecting code into the kernel, it gains full control over how the system enforces its basic operations. This allows it to tamper with kernel data structures and hook kernel routines, so it can hide its own processes, files, network connections, and other artifacts from normal security tools and user-space investigators. The depth of access and the ability to alter fundamental OS behavior make this type the most effective at concealing attacker activity.

In contrast, library-level rootkits patch user-space libraries to influence how programs run, but they don’t modify the kernel itself. Hypervisor-level rootkits reside in a virtualization layer above the OS, controlling the guest from outside the kernel. Hardware/firmware rootkits hide within the hardware or its firmware, independent of the OS kernel.