I am using WMI to obtain members of server local groups, as well as the SIDs of the members. The WQL queries work for members that are local users, local groups, AD domain users and AD domain groups. However when the script is looking at members that happen to be SQL Server related, it cannot find the object in the class it thinks it should look at, and therefore I don't get the SID of the members. For example, here are some queries constructed dynamically for group members that happen to be SQL Server related:

select SID from Win32_SystemAccount where Domain='NT SERVICE' and Name='SQLBrowser'
select SID from Win32_SystemAccount where Domain='NT SERVICE' and Name='MsDtsServer100'
select SID from Win32_SystemAccount where Domain='NT SERVICE' and Name='SQLAgent$SQLEXPRESS'
select SID from Win32_SystemAccount where Domain='NT SERVICE' and Name='MSSQL$EPROVISIONAPP'
select SID from Win32_SystemAccount where Domain='NT SERVICE' and Name='MSOLAP$EPROVISIONAPP'
select SID from Win32_SystemAccount where Domain='NT SERVICE' and Name='ReportServer$EPROVISIONAPP'
select SID from Win32_SystemAccount where Domain='NT SERVICE' and Name='SQLAgent$EPROVISIONAPP'

The queries above do not return any result, even though the PartComponent of such members tells me that the member is from the Win32_SystemAccount class, and the Domain is 'NT Service'.

On the server, if I look at Local Users and Groups -> Groups, and look at the properties of a group, say "SQLServerSqlAgentUser$myservername$SQLEXPRESS", it has one member "NT SERVICE\SQLAgent$SQLEXPRESS (S-1-5-80-592940576-165...". I cannot see the entire value of the SID.

I cannot figure out how Microsoft is pulling the SID of such members, where it is getting them from.

Any ideas?