I just discovered almost same problem with one of my old VLC builds (1.1.11) on my old computer, containing Chinese extension under FileExt registry key, which appears to be created WHEN I started a desktop capture session via VLC, containing the filename of this capture, resulting in a Chinese extension which is unreadable:
Extension has no translation from Chinese to English with success, and it has no sign of infection but its creation/last write date and time refer to the run time of VLC and the key is associated with VLC.exe on the right pane, screenshot cropped.
Is it a known bug, a corruption occured by VLC?