From what I can tell, Microsoft signed DigiCert's certificate, and DigiCert signed CrowdStrike's certificate, and CrowdStrike signed the driver file. Windows k

From what I can tell, Microsoft signed DigiCert's certificate, and DigiCert signed CrowdStrike's certificate, and CrowdStrike signed the driver file. Windows kernel signing does not work like Apple's Big Brother approach, it uses a set of certificate authorities. Microsoft does have a program for verifying drivers: WHQL, which you may recognise from the slower driver that Windows Update installs for your GPU before you download the faster one that didn't pass Microsoft's verification from the manufacturer's website. CrowdStrike doesn't seem to be WHQL-certified.