I found this blog post talking about the top 7 ways that a hacker will attempt to hack into your WordPress script and into your web hosting account.
3 of the top 5 methods is utilizing known vulnerabilities in old and outdated scripts, themes, components, plugins, and extensions. This underscores why it is so very important that you keep all scripts, not just WordPress, and all extensions to those scripts, up-to-date.
1. Upgrade to the newest version of WordPress
2. Upgrade all your themes and plugins to their newest versions
5. Know what other web applications you have installed
I encourage you to take a moment and read through this post. It is very well written. And further explains how you can keep your hosting account safe and secure.
Props to Mr. Maunder for a well written article.