Moon.exe belongs to the New Game Plus secret-ending route. It requires the first-run collectibles, Parachute.exe, the Data Diver, the White Tiger Doll, and the six secret tapes.
Before attempting Moon.exe
This is not a first-playthrough shortcut. Published ending guides place it in New Game Plus after collecting the 24 standard dolls/cartridges, completing Parachute.exe, retaining Data Diver, and obtaining the White Tiger Doll as the twenty-fifth collectible.
Why the permissions matter
Moon.exe is associated with the glitched-permissions step that exposes the hidden path. The route also requires six secret tapes and assembly of their result before the final escape sequence.
Because this path contains ending spoilers, the complete sequence is kept on the dedicated secret-ending page rather than duplicated here.