To change the permissions of the files you will have to type below mentioned command at your command prompt:

find /home/username/public_html -name “*.php” -exec chmod 644 {} \;

To change the permissions of the folders and sub folders you will have to type below mentioned command at your command prompt:

find /home/username/public_html -type d -exec chmod 755 {} \;

The correct permissions for SuPHP incidentally are as follows:

0600 PHP Scripts
0755 Non-PHP Scripts (*.cgi, *.pl, *.pm, *.py, *.e)
0644 Non-Script Files (Images, CSS, HTML, Templates, Etc)
0755 All Folders (Any folder you would find below public_html)

https://forums.cpanel.net/threads/how-to-scan-for-files-folders-with-777-permissions.152453/