Дмитрий

Нашел решение которое выводит ФИО из AD по логину.
Необходимо подключить System.DirectoryServices

private void getUser(string uLogin)
        {
            string filter = string.Format("(&(ObjectClass={0})(sAMAccountName={1}))", "person", uLogin);
            string domain = "[ВАШ_ДОМЕН]";
            string[] properties = new string[] { "fullname" };
 
            DirectoryEntry adRoot = new DirectoryEntry("LDAP://" + domain, null, null, AuthenticationTypes.Secure);
            DirectorySearcher searcher = new DirectorySearcher(adRoot);
            searcher.SearchScope = SearchScope.Subtree;
            searcher.ReferralChasing = ReferralChasingOption.All;
            searcher.PropertiesToLoad.AddRange(properties);
            searcher.Filter = filter;
 
            SearchResult result = searcher.FindOne();
            DirectoryEntry directoryEntry = result.GetDirectoryEntry();
          
            string displayName = directoryEntry.Properties["displayName"][0].ToString();
            MessageBox.Show(displayName);
        }