We have a similar issue where there are accounts from different domains on the computers and we need the domain back. Unfortunately the SID fetch doesn't work I think for local accounts and the domains the computer used to be joined to in some cases, so it didn't return all results.
This was the best solution I found for us:
Admin = $_.GetType().InvokeMember("AdsPath", 'GetProperty', $null, $_, $null)
will return results like
WinNT://#domain#/#account#
or WinNT://#domain of computer#/#computer-name#/#account#
for local accounts
$servers= get-content 'C:\temp\work\localadmins\serverlist_in.txt'
$output = 'C:\temp\work\localadmins\serverlist_out.csv'
$results = @()
foreach($server in $servers)
{
$admins = @()
$group =[ADSI]"WinNT://$server/Administrators"
$members = @($group.psbase.Invoke("Members"))
$members | foreach {
$obj = new-object psobject -Property @{
Server = $Server
Admin = $_.GetType().InvokeMember("AdsPath", 'GetProperty', $null, $_, $null)
}
$admins += $obj
}
$results += $admins
}
$results | Export-csv $Output -NoTypeInformation