Wordpress is well known to be a popular backdoor for attackers to gain access to websites. Usually exploiting vulnerabilities from out of date wordpress plugins is the most popular methods.

Consider implementing the following measures:

1. Regular Updates: Ensure that your WordPress core, themes, and plugins are regularly updated. Updates often contain security patches.

2. Strong Passwords and User Permissions: Use strong, unique passwords for your WordPress admin area, FTP accounts, and database. Limit user permissions and avoid giving admin access unless absolutely necessary.

3. Website Firewall and Security Plugins: Install a website firewall and security plugins. These tools can help in blocking malicious traffic and scanning for vulnerabilities.

4. SSL Certificate: Use an SSL certificate to encrypt data transmitted between your server and your users’ browsers. This is especially important if you handle sensitive information like credit card details.

5. Regular Backups: Regularly back up your website. In case of a security breach, you can restore your site from a backup without losing data.

6. Hosting Environment: Choose a secure hosting environment. Some hosting providers offer specialized WordPress security features.

7. Disable File Editing: Disable file editing via the WordPress dashboard. This prevents attackers from modifying your files even if they gain admin access to your WordPress.

8. Two-Factor Authentication: Implement two-factor authentication for logging into your WordPress site. This adds an extra layer of security.

9. Monitoring and Auditing: Monitor your website for suspicious activities and audit logs regularly. This helps in identifying and responding to security threats promptly.

10. Limit Login Attempts: Limit the number of login attempts from a single IP address. This can help prevent brute force attacks.

11. Disable Directory Listings: Prevent directory listings of site files. This can be done by adding a line of code in your .htaccess file.

12. Regular Security Scans: Conduct regular security scans to check for malware and vulnerabilities.