Provide those details so I can narrow down the solution.
Open the file in a Hex Editor (like HxD or Ghex ) to check the Magic Bytes . A ZIP file should start with 50 4B 03 04 . If these are altered, the file won't be recognized. File: Vampyr.zip ...
Use the file command to confirm it is a true ZIP archive and not a renamed file. file Vampyr.zip Use code with caution. Copied to clipboard Provide those details so I can narrow down the solution
Check for hidden files or interesting naming conventions. unzip -l Vampyr.zip Use code with caution. Copied to clipboard If these are altered, the file won't be recognized
Use John the Ripper or fcrackzip with a wordlist like rockyou.txt .
Scan for nested files or "carved" data that might be appended to the end of the archive. binwalk -e Vampyr.zip Use code with caution. Copied to clipboard 4. Extraction & Flag Capture Once the password is found or the file is repaired: Extract: Unzip the contents to a folder.