Definition - What does BIOS Rootkit mean?
A BIOS rootkit is a type of application that resides within a computer’s memory hardware and is used for remote system access and monitoring. A BIOS rootkit allows system administrators and original equipment manufacturers to remotely access and update a system. It is stored and accessed from the computer’s physical memory (RAM).
Techopedia explains BIOS Rootkit
A BIOS rootkit can also be exploited by hackers and crackers to illegitimately gain access to a system. In such an event, it is infested with a malicious code, which is generally undetectable, although it can be removed by most anti-virus and security software.