Bootkitty - The First UEFI Bootkit That Targets Linux (youtube.com)
UEFI bootkit is malware that targets the master boot record instead of the root file system. It can stay on the machine even after a full OS reset. So far, hasn't been seen in the wild, and is just a PoC, but shows Windows being bad doesn't mean Linux is perfect.
Boot Kitty uses a SelfSignedCertificate, so can't run on systems that have UEFI SecureBoot enabled. It uses Logofail to bypass SecureBoot protections. Its image size overloads some stuff and gets to the MachineOwnerKeyDatabase. It disables Grub's security checks and other self-protective things.
Shows updating UEFI is important to close attackVectors for bootkitHacks.