: Open the archive with tools like 7-Zip or WinRAR. Look for file extensions inside the archive:
Never extract an unknown .rar file without a security check. ARYETTMCBK12 rar
If this file is related to a specific software project or a private data backup, could you provide about where you found it or what it is supposed to contain? : Open the archive with tools like 7-Zip or WinRAR