Interesting, that truly is issued by DigiCert. The end-entity certificates I see for microsoft.com, azure.microsoft.com, portal.azure.com are all issued by: C

Interesting, that truly is issued by DigiCert. The end-entity certificates I see for microsoft.com, azure.microsoft.com, portal.azure.com are all issued by: C = US, O = Microsoft Corporation, CN = Microsoft Azure RSA TLS Issuing CA 0X [where X varies] In any case, I just analyzed DigiCert's CRLs and it doesn't look like they've done many revocations yet. These are the only CT-logged certs revoked in the last 24 hours with reason code 4 (required when domain validation is done improperly): https://gist.github.com/AGWA/2d22a1a94ef80ccdb38e3248323f434c https://gist.github.com/AGWA/2d22a1a94ef80ccdb38e3248323f434... I don't see any Microsoft/Azure domains in that list.