CMS-CSE/core/submit/cms.parametres-download-backup-zip.php

<?php

if(core::ifPost("from")){
    header('Content-type: application/octet-stream;');
    header('Content-Transfer-Encoding: base64');
    header('Content-Disposition: attachment; filename="'.core::getPost("file").'"');
    readfile(DIR_BACKUP.core::getPost("file"));
}