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Microsoft begins cracking down on people dodging Windows 11's system requirements
(www.xda-developers.com)
This is a most excellent place for technology news and articles.
BIOS and UEFI bootkits require special vendor tools and vendor signed firmware binaries to overwrite the SPI memory. Standard anti-virus software can not remove them, once they have been installed.
You are right, you patch your bios with a vendor program. However regular virus scanners will detect it and motherboard manufacturers provide bios flashing tools. But AMD has said they will not provide firmware tools for their old CPUs.