This is not ActiveDirectory authentication, its is NTLM - Windows NT4

[ianclegg]

Windows NT4 was released with NTLM authentication. Windows 2000 was released with Active Directory and Kerberos authentication. In fact, NTLM is sometimes used when Active Directory is not available.

Furthermore, because this is NTLM - this does not support Active Directory groups, which are passed as SID's in the PAC structure of Kerberos service ticket.

You should probably rename this package Microsoft.AspNetCore.Authentication.NTLM - its misleading to include Active Directory in the name when it has no technical relationship or dependency on ActiveDirectory.