- Only give absolutely needed permissions to your mods and admins
- Create a separate admin account that is the "super admin" (in config) with plugin and theme permissions. Your day to day admin user should not have any of these permissions.
- Require password changes to your Mods and Admins every XX days
- I'm paying for password manager software for my mods/admins
- htaccess password protect both AdminCP and ModCP. Don't give out the password via the forums or through pm.
- Use a Web Application Firewall. SAAS versions include
https://www.cloudflare.com ,
http://cloudproxy.sucuri.net ,
http://www.incapsula.com
- Two factor authentication for moderators and admins.
- Consider globally disabling more dangerous PHP functions