Super-UEFIinSecureBoot-Disk

You can edit UEFI drivers from the operating system's bootloader, and you can even flash the UEFI itself from the OS in most computers. While secure boot. Failing that, you can shim a preloader between the bootloader and the UEFI and load arbitrary drivers despite secure boot, like is done here : https://github.com/ValdikSS/Super-UEFIinSecureBoot-Disk Any sufficiently motivated attacker can make a UEFI rootkit happen, and it's in the wild right now. TPM really do offer no protection to users, either against userspace malware, or rootkits. It's purely about DRM.