The Vilna Gaon had no surname, nor did his ancestors, brothers, sons.
It was certainly NOT KREMER.
That was used only by his great-great grandfather Moshe Kremer as a discription of his occupation, meaning a storekeeper either in a shop or more likely in a market.
Certain descendants of the Gaon's brother Moshe adopted the surname Kremer.
I have corrected the profiles of many relatives of the Gaon many times but some/one of the 24 profile managers keeps putting back the erroneous appellation "Kremer".
Please desist.