Is this a password-protected file from an Alternate Reality Game? If so, the "piece" might be a password or a missing file fragment hidden in a separate clue.
If you can tell me or what you are trying to do with it (e.g., extract it, complete a set, find a password), I can give you a much more specific answer. Sexy-Serial-Killer.rar
Is this a specific drop from a creator or a clothing brand? Some niche brands use file-naming conventions for their collections. A Specific Game or Mod: Is this a password-protected file from an Alternate