“That said, its existence underscores an important message: UEFI bootkits are no longer confined to Windows systems alone.”
Bootkitty patches integrity checks in memory and hunts for hardcoded byte patterns, so it only fits a few Ubuntu configurations and crashes the rest. It is signed with a self-signed certificate, so Secure Boot blocks it unless the attacker’s certificate is installed. Linux users have long treated bootkits as a Windows problem. The machines with Secure Boot switched off are the ones it was built for.