Leo never posted the password. He didn't have to. The file was already extracting itself into the real world, one dimension at a time. If you'd like to explore this story further:
Should I describe when the "flattening" reaches the rest of the city? flatalice.7z
The legend of flatalice.7z wasn't about what was in the file. It was about what the file did to you. It simplified you. It removed the weight of existence, leaving behind only the pure, flat data of who you were. Leo never posted the password