Because this looks like a specific local filename or a unique database ID, there is no public "write-up" for it. However, if you are seeing this name while working with video files, it likely relates to one of the following scenarios: Possible Origins
High-end editors (like Magix Movie Edit Pro or Adobe Premiere) often generate alphanumeric strings for proxy files to handle high-resolution video. Erox In 9vf9d4de10144 mp4
If the file won't play, it may be a "fragment" of a larger download that was never completed. Because this looks like a specific local filename
Cloud storage services or private servers often rename files to unique IDs like 9vf9d4de10144 to prevent direct link guessing. Erox In 9vf9d4de10144 mp4
Tools like MediaInfo can reveal the original metadata, including the software that created it and the original filename.