.PIZ File Extension
What is a PIZ file?
A PIZ file is a compressed .ZIP archive that has been renamed with the extension reversed. It contains one or more files that have been compressed with Zip compression. PIZ files are often used for hiding the file type when sending zipped email attachments so that email server filters don't block the message.
If you receive a PIZ file you should verify the identity of the sender in order to ensure that the file does not contain malware. Once you verify that the file is safe, rename the ".piz" extension to ".zip" and open it with any Zip decompression utility. Some popular programs are WinZip, Win RAR, 7-Zip, and Stuffit Deluxe.