WebsiteDefender is an online service that monitors your website for hacker activity, audits the security of your web site and gives you easy to understand solutions to keep your website safe. With WebsiteDefender you can:

• Detect Malware present on your website
• Audit your web site for security issues
• Avoid getting blacklisted by Google
• Keep your web site content & data safe
• Get alerted to suspicious hacker activity

It has an easy to user interface, it picks up all kinds of issues such as malware, reverse shells like c99, obvious stuff like outdated Plugins and WordPress core, weak passwords, bad configurations (including .htaccess config) and much more.
Each alert is well explained and will help you to solve any issues the system finds on your blog/site.
The great value with this for me is once you are subscribed, you will be automatically alerted of new issues by email as and when they occur. This will help you keep your website secure and will let you know immediately if any issues develop.
They’ve even released two WordPress plugins which you can find here:
WP Security Scan & Secure WordPress
You can check out the website here and sign up for a free account to test it out:
http://www.websitedefender.com/
They are on Twitter too @WebsiteDefender & Facebook.