The search query suggests a few possibilities, mostly related to (OpenIV Package format - .oiv/zip) or a general CTF "ZipLock" challenge. Given the potential ambiguity, 1. GTA IV "OTV" Modding (OpenIV)
(e.g., a specific hacking challenge, a game mod, or a file you found?) Where did you download otv4.zip from? otv4.zip
Checking the file type with file , looking for hidden metadata with exiftool . The search query suggests a few possibilities, mostly