The filename "video_2021-12-21_18-05-55.mp4" is a generic timestamp format used for media exported from Telegram, commonly appearing in archives from late 2021, including cryptocurrency, gaming, or personal recordings. Without further context on the video's content, it cannot be tied to a specific viral event, though it may stem from social media, ARG, or private archives. For further analysis, you can search for the video's content description in online archives.