Maybe nest an install script in cpu microcode that executes at random power ons to install a minimal windows IoT for the sole reason of highjacking boot sequences?
Yeah. I dual boot on an old laptop just in case I happen to need windows for something and sometimes the windows partition puts itself at the top of the boot order, but my Debian partition is still there and I just have to put it back at the top.
yeah windows sneeky snacking the bootloader was one of the reasons i quit dual booting a decade ago, have not missed windows a single moment since then
I don't doubt that it can happen but Windows has never messed with my GRUB even on major updates and even, IIRC, when "upgrading" from Windows 10 to 11.