just as important as having backups in place, it is worth installing security plugins to increase the security level of your website, otherwise you might up having to restore your backups often, without fixing the underlying security problems that are repeatedly exploited by attackers.
Unfortunately, if you are looking for a plugin that keeps you protected after you install it, without any manual effort, you will be disappointed, because there is no such thing. Honestly, every plugin that claims that it provides 100% security by just installing it, should not be taken seriously.
We have just released MVIS Security Center, a new security plugin, last week that helps you locking down your website by clearly showing you any security problems and providing you with all the information needed to eliminate them. Most of the security topics of the official Hardening WordPress Guide are covered and additional checks have been added.
The plugin does not automatically eliminate the identified problems for you, but it really helps you in securing your websites according to recognised security best practices, by showing you what the problems for your specific website are and how to get rid of them.
Additionally, and this is unique, from within the plugin you can subscribe to MVIS PROtection, which is a service that monitors your WordPress version and which plugins and themes are installed and sends alerts to your e-mail address as soon as vulnerabilities have been publicly disclosed that affect one of your installed components. This is especially convenient, because you don't even have to login to the admin interface, but automatically receive the alerts in your inbox and are able to take the required actions immediately.
The plugin is free and because we are currently in the beta phase, the subscription is free for the next three months.
Give it a try and let me know how you like it and if there is anything else you would like to see covered by it.