Confirm-DomainAdmin

#requires -Version 5
function Confirm-DomainAdmin
{
    [cmdletbinding()]

    Param(
        [Parameter(Mandatory = $True, Position = 0,ValueFromPipelineByPropertyName = $True)]
        [Alias('Username')]
        [string[]]$SamAccountName
    )

    Begin{
        # This whole statement will recursively find the usernames in the Domain Admin group, even if someone does something funny like renaming the group or moving it.
        $SidAsByteArray = ([adsi]'').ObjectSid[0]
        $Offset = 0
        $DomainSid = [System.Security.Principal.SecurityIdentifier]::new($SidAsByteArray,$Offset).Value
        $Searcher = [adsisearcher]"ObjectSID=$DomainSid-512"
        $DN = $Searcher.FindOne().Properties.distinguishedname
        $Results = [adsisearcher]"(&(objectClass=user)(memberof:1.2.840.113556.1.4.1941:=$DN))"
        $AdminUsernames = $Results.FindAll().Properties.samaccountname
    }

    Process{
        Foreach($User in $SamAccountName)
        {
            [pscustomobject]@{
                Username      = $User
                IsDomainAdmin = $User -in $AdminUsernames
            }
        }
    }

    End{}
}