Sean Fisher

This plugin will hide WordPress Admin (/wp-admin/) when a user isn’t logged in. If a user isn’t logged in and they attempt to access WP Admin directly, they will be unable to and it will return a 404. It can also rename the login URL.
Also, you can add HTTP authentication directly from WP Admin and add custom username/password combinations for the HTTP auth or use the WordPress credentials.
This doesn’t touch any .htaccess files or change the WordPress core files. All the CSS/Images under /wp-admin/ are still accessible, just not the .php ones.
If you enable HTTP authentication, it will add HTTP authentication to the PHP files in /wp-admin/.
To contribute to the development, check out <a href="https://github.com/srtfisher/Lockdown-WPAdmin" rel="nofollow ugc">the GitHub Repository</a>.

Lockdown WP Admin

Lockdown WP Admin conceals the administration and login screen from intruders. It can hide WordPress Admin (/wp-admin/) and and login (/wp-login.

Adam Sewell

The Shopp Lockdown plugin watches for failed transactions on any Shopp payment gateway and limits the transactions to X number of tries.
This comes in handy when gateways like Authorize.Net limits your account after so many failed transactions.
Without this plugin, an attacker could initiate a temporary DoS attack by trying too many fraudulent cards in a short period of time.
This plugin has been tested with Shopp 1.2.x and Shopp 1.3.x

Shopp Lockdown

The Shopp Lockdown plugin watches for failed transactions on any Shopp payment gateway and limits…

Lockdown WP Admin vs Shopp Lockdown