In many parts of the world, "12.03" refers to March 12th or December 3rd . Files named after dates often appear in digital mysteries or ARG (Alternate Reality Game) narratives as "lost" logs or evidence found on old hard drives.
It could represent Version 12.03 of a software patch or mod, similar to "creepy" legacy versions found in communities like Minecraft .
A story about a corrupted software update (Version 12.03) that begins changing the user's computer—or reality. Which of these plot lines sounds most interesting to you? How to Open RAR Files on Windows, Mac, and Mobile - Avast