Brute Force Attack is a daily problem for WordPress sites. What’s interesting is that you cannot prevent it from happening. It’s unavoidable. You can only make harder for the attacker to attack your sites.
If we use CMS with login feature to manage our content, we cannot remove/disable the login functionality because we need it to get access to manage the site.
You can use the strongest password, two factor authentication, etc. But it will not stop the attack to your site.
Every single login attempt will cost you server resource. You cannot cache this page to reduce the impact because WordPress need to validate each login attempt.
But, we can try to discourage attacker by blocking IP addresses they use. If you use relatively good hosting, you probably have firewall system installed in your server to log and block attacker. But you can also install security plugin to add another layer of security. Several plugin for WordPress brute force protection:
- Limit Login Attempts : un-maintained plugin, if I’m not mistaken WP Engine auto-activate this plugin for sites hosted there.
- BruteProtect : Use their server to log IP addresses, kinda like Akismet for brute force attack. You need to register to their site to get API key for each of your site. Currently owned by Automattic.
- Login Security Solution : similar with limit login attempt, maintained. And have multi-site support. This is the plugin I’m using.
- And a lot more alternative…
It will reduce their attack, but because they seem to have unlimited number of IP Address, it’s actually (kinda) useless method to try to discourage them.
Quoting from Matt Mullenweg:
Supposedly this botnet has over 90,000 IP addresses, so an IP limiting or login throttling plugin isn’t going to be great (they could try from a different IP a second for 24 hours).
You can also read other sources to understand the scale of the attack:
- WordFench : Large distributed brute force attack underway at 40,000 attacks per minute.
- Sucuri Blog: Understanding Denial of Service and Brute Force Attacks – WordPress, Joomla, Drupal, vBulletin
Every single day in each sites I got hundreds of failed login attempt. Probably tens of thousands if it’s not protected by firewall and security plugins. It happen in every single site. Not even one site is free from brute force attack.
Several days ago, I ask for advice at Theme Hyrid Forum (private forum replies). I got several response. And from their response I create a custom solution for my sites and my clients sites.
I tested it in 10 different sites for 24 hours, the result is amazing. I got almost zero login attempt.
Even though it’s still premature to say that this solution is working. In this post I would like to share the custom solution I build to solve this problem.