Depending on how the UEFI is configured, a simple copy/paste command, executed either by the malicious image or with physical access, is in many cases all that’s required to place the malicious image into what’s known as the ESP, short for EFI System Partition, a region of the hard drive that stores boot loaders, kernel images, and any device drivers, system utilities, or other data files needed before the main OS loads.
Right, I know EFI images are stored in the EFI partition, but with secure boot, only signed images can be executed, so they’d need to steal someone’s signing key to do this.
This is way before reaching your bootloader. It’s about the manufacturer logo that’s displayed by UEFI while doing the whole hardware initialization.
That’s… Stored in the EFI partition or changeable in userspace?
(from the article)
Right, I know EFI images are stored in the EFI partition, but with secure boot, only signed images can be executed, so they’d need to steal someone’s signing key to do this.