There are many fan-made "MP4" files within the Analog Horror community, often using generic names like FILE-105 or REC-105 .
There is currently no widely known internet mystery, horror series, or viral video specifically titled BANK-105.mp4
In certain video game lore (like SCP Foundation or Roblox horror games), files are often named with prefixes like BANK followed by a number. There are many fan-made "MP4" files within the