>The fact that secure boot can "mitigate" some of this attack right now is mostly due to the attacker being lazy or deploying an unfinished product. The researchers describe this as "unless they install the attackers certificate", which is a nice way of saying that the attacker has not spent much time fishing through DKMS and abusing the keys used for this purpose.

Can you explain, or link to a source explaining this?

It was just a way for Microsoft's partners to limit the ease with which one can install alternative OSes. Try explaining to your mother how to disable SecureBoot to install Ubuntu. It used to be a single sentence - pop the CD in and follow the instructions, but Microsoft couldn't have that. As is always the case with Microsoft, security is never the goal unless they gain a competitive advantage or make it harder for their customers to move away in the process.

What makes you think that? Secure Boot prevents this rootkit from running and is the recommended mitigation:

> Bootkitty is signed by a self-signed certificate, thus is not capable of running on systems with UEFI Secure Boot enabled unless the attackers certificates have been installed.

> To keep your Linux systems safe from such threats, make sure that UEFI Secure Boot is enabled

In fairness, the blog post confusingly says this in the next bullet point:

> Bootkitty is designed to boot the Linux kernel seamlessly, whether UEFI Secure Boot is enabled or not, as it patches, in memory, the necessary functions responsible for integrity verification before GRUB is executed.

However, this would still require Rootkitty to have gained execution already, which it wouldn't be able to if Secure Boot was enabled and the malicious actor's certificates weren't installed.

"Secure boot" is not actually meant to improve security.

It exists as a moat to make it harder to install Linux on your (Microsoft) PC.

The article says that Bootkitty does not work if Secure Boot is enabled. How do you figure Secure Boot made things less secure?

What?

I agree the move to UEFI added a huge new attack surface and that most UEFI implementations (notably, even the open source ones) are teeming with horrible bugs.

And yes, then linking the trust architecture for Secure Boot so deeply with UEFI means that UEFI bugs are also Secure Boot bugs.

But to say this is less secure? No way. Traditional BIOS-based MBR backdoors are like 1980s oldschool classic stuff. Most adversaries would require a good degree of development work to backdoor / root kit a PC they were given with Linux, Secure Boot, and an encrypted filesystem. With a BIOS based PC there would literally be nothing to do.

It's more secure than not having Secure Boot.

And significantly more complicated to setup and maintain in my limited experience :|

UEFI itself is way too complex, has way too much surface (I'm surprised this didn't abuse some poorly written SMI handler), and provides too little value to exist. Secure boot then goes on to treat that place as a root of trust, which is security architecture mistake, but works ok in this case. This all could be a lot better.

Not everyone is into pirates you know?

Nothing. This is just a proof of concept that is ridiculously easy to detect. If your attackers can drop files in your /boot or /boot/efi directory, I think you have much worse things to worry about than this.

In fact, this bootkit would be about the least thing I would worry about. Because by the time an attack can write to /boot, they can also write to /etc/init.d . And the later is not protected by "secure boot".

It means "just trust us" is not and never was secure.

Trustworthy people don't ask you to trust them.