I have a web server in the cloud hosted with Amazon cloud. It's a linux server.
Not long ago, the website was badly compromised due to flaws in the PHP code. So the hacker was able to 'inject' some sort of code and was able to make changes to the php file.
The security holes in the PHP code have been patched. However, we're still worried of something like that happening in the future.
As it stands, the files and folders on the public facing side seem to have the 775 permissions. The owner of this group is the actual EC2-user, which is the default user. However you can only access the files/folders as this user if you have a special private key, otherwise you can't (well, the hacker evidently did when the site was vulnerable).
Question is, if this was you, how would you tighten the security? Would you create a new user and set all files and folders on the public side to have 755 permissions and make that user the owner of those files/folders?