Rootkits that pose the biggest threat to any OS are those that infect the firmware part of the targeted device. Therefore, the correct answer is: B. firmware.
In Computer technology, a rootkit is a type of trojan which refers to a set of tools or software program that is designed and developed to gain access and control of an end user's computer system without revealing its presence i.e it hides its presence.
In Computer technology, a firmware refers to a kind of system software and it is primarily preinstalled on electronic devices such as blenders, automobiles, and televisions.
In conclusion, rootkits that pose the biggest threat to any operating system (OS) are those that are designed and developed to infect the firmware part of the targeted device.
Complete Question;
Rootkits that pose the biggest threat to any OS are those that infect what part of the targeted device?
A. firmware
B. testware
C. middleware
D. fireware