Content Management System or better known as CMS such as WordPress, Joomla and etc. are commonly used by user's to develop website.
However these CMS are also vulnerable because they are built on open source frameworks.
There are certain things you can do to protect your site from vulnerabilities.
1- Use captcha at your admin login page
2- Ensuring that the platform and the scripts that you have installed are updated.
3- Make sure that your website is always backed up. The regular backup would ensure that your data remains safe.
4- Hide your admin panel (admin login page)
5- Only installed theme/script/plugins from trusted source.
6- Protect your website contact form to avoid spamming incident.
7- Use strong, not easily guessed password for your admin site.
8- Remove unwanted/unused theme and plugins as it might contain any loopholes for malware attack due to no updates.
9- Remove inactive admins/FTP users.