I am yet to see _any_ consumer-oriented motherboard where SMBIOS descriptions have even a passing relationship to the actual hardware. I would not be surprised if this malware would also fail in 50% of real hardware out there. But I also guess malware can afford this failure rate; as long as it guarantees it also fails on 100% of VMs/debuggers, it is worth it.

But if these assumptions are true then I'd presume malware authors would do timing checks rather than the trivially "emulable" SMBIOS.