The file itself is encrypted, the file is compressed, and a password is set.

1, the file itself is encrypted: someone will encrypt the entire ISO file to protect the contents of the ISO file. This means that you need to enter the correct password to decrypt and open the file, and the file provider or creator will tell you the correct password when sharing or providing the file.

2. The file is compressed and password is set: Quark ISO file is compressed and password protected first. In general, you need to extract the file and enter the correct password to get the ISO file, and then use the appropriate tools to open the ISO file.