Do you have a where you found this file, or can you describe the contents if you've already opened it?
: If you downloaded this file from an untrusted pop-up or an unsolicited email, it is highly recommended that you do not open it , as .rar files are frequently used to disguise executable malware.
: Occasionally, hardware components use alphanumeric codes like this for compressed update packages.
: Many "M13" or "SHP" designations refer to specific game assets (such as Madden 13 or Command & Conquer SHP files).
: It could be a private backup file from a specific user or local server. How to Safely Handle This File