no default password for ZArchiver. If you are being asked for a password while trying to extract a file, it means the person who created that specific archive (the .zip, .7z, or .rar file) encrypted it with a password. Google Books Where to Find the Password
If you have downloaded a file and ZArchiver prompts you for a password, follow these steps: password of zarchiver
If you’ve ever downloaded a compressed file (like a .zip or .7z) and tried to open it with no default password for ZArchiver