Not sure what you ask. Files all over your Osclass should be 644 and folders 755. No need for a special script. Of cource it also depends of your hosting type.
If it is shared then it should be already preconfigured. If not, then it is a poor service.
If you manage your server then if you don't know how, find someone to help you out. Security is very important for all scripts you run online.
Also if you are managing yourself the server or the plan, you can find information on the internet about it, just search for Wordpress (instead of Osclass). Wordpress settings for security files/folders/user in hosting is the very same as with Osclass. There is plenty of information about it.