Ok open config.php change the security code to something else, doesn't matter what it is, but don't leave it to default.
Delete modules/WebMail/mailattach.php it has a security issue that leaves your site open to exploits.
check images/admin/code_bg.jpg for your security image for admin.
check modules/Your_Account/images/code_bg.jpg for your security image for users.
You actually installed 6.5

Go back over to nukecops and look for secfix 3, install that, it fixes a myriad of issues.