As we explained in a previous article – how to protect against Lojax rootkit, the only way to get rid of these type of malware is to re-flash the firmware in the BIOS/UEFI chip on your motherboard.
At this point not many security products are capable of scanning the BIOS/UEFI firmware and therefore these kinds of rootkits are very dangerous.
Some of the malware these days are targeting even the firmware stored on a small BIOS/UEFI chip that resides on your computer’s motherboard.