ueprereqsetup_x64.exe UAC Warning: Publisher unknown

When I try to install UE via the Epic Games Launcher the Windows 10 UAC window comes up asking if I really want to install ueprereqsetup_x64.exe from an Unknown publisher.

Why is the executable not signed? My expection is that Epic should sign these executables. Is there any other way, checksum, digital signature, that I can use to verify the files integrity?