: If you must open it, use a tool like WinRAR or 7-Zip to "Open Archive" (viewing the file list) rather than "Extract" to see the file extensions inside first.
: Compressed assets or patches for specific video games, often found on community forums or niche modding sites. H09.rar
Could you provide more , such as where you found the file or what hardware/software you were working with when you encountered it? : If you must open it, use a