Problem:

When you visit your WordPress website you are randomly redirected to unwanted websites.

Verification:

• Log in your website as an Administrator.
• Go to Appearance >> Theme File Editor.
• Click on the Theme Functions link on the right side.
• Verify if malicious code was injected into the functions.php file. Example of malicious code:

  <?php @ini_set('display_errors', '0'); 
  error_reporting(0); 
  global $zeeta;

• Download the wp-config.php file to your machine via FTP or SSH.
• Verify if malicious code was injected into the wp-config.php file. Example of malicious code:

  include_once(ABSPATH . WPINC . '/header.php');

Solution:

• Stop the website.
• Download the whole website to your local machine.

  cd /var/hosting/huybien.com
  ls
  sudo zip -r huybien.zip /var/hosting/huybien.com/html

• Download the latest version of WordPress.
• Unzip and the latest version of WordPress to a new huybien folder.
• Copy the wp-content/uploads folder, the wp-config.php and ads.txt file from your original website to the new huybien folder.
• Review and remove all the suspicious contents in the wp-content/uploads directory in the new huybien folder.
• Review and remove all the suspicious contents in the wp-config.php file in the new huybien folder. You may need to remove malicious code such as

  include_once(ABSPATH . WPINC . '/header.php');

• Go to the wp-content\themes folder of the new huybien folder. Manually re-download and unzip all the necessary themes. Examples:
  https://wordpress.org/themes/twentyfourteen/
• Remove all the unused themes.
• Go to the wp-content\plugins folder of the new huybien folder. Manually re-download and unzip all the necessary plugins. Examples:
  https://wordpress.org/plugins/advanced-nocaptcha-recaptcha/
  https://wordpress.org/plugins/classic-editor/
  https://wordpress.org/plugins/contact-form-7/
  https://wordpress.org/plugins/highlighting-code-block/
  https://wordpress.org/plugins/insert-headers-and-footers/
  https://wordpress.org/plugins/simple-history/
  https://wordpress.org/plugins/top-10/
  https://wordpress.org/plugins/updraftplus/
  https://wordpress.org/plugins/wp-cerber/
  https://wordpress.org/plugins/wp-mail-smtp/
• Pay attention to the plugins that were closed due to Guideline Violation. Remove all the unused plugins.
• Remove all your website content in the root directory in your hosting server.

  cd /var/hosting/huybien.com/html
  sudo rm -rf *
  ls -a

• Zip and upload the new folder (without the folder name) to your hosting server. The typical path is /home/ubuntu.
• Unzip the new content to your root website directory.

  cd /home/ubuntu
  ls
  sudo unzip huybien.zip -d /var/hosting/huybien.com/html

• Start the website.

Configuration:

• Log in your website as an Administrator.
• Change your Administrator’s password.
• Change file owner and group to www-data:

  sudo chown -R www-data:www-data /var/hosting/huybien.com/html

• IMPORTANT STEP – Set minimum permissions for folders and files:

  cd /var/hosting/huybien.com/html
  sudo find . -type d -exec chmod 755 {} \; # directory permissions rwxr-xr-x
  sudo find . -type f -exec chmod 644 {} \; # file permissions rw-r--r--

• Remove all the unused plug-ins or themes.
• Install, activate and configure a CAPTCHA plug-in to protect Login Form, Registration Form, Lost Password Form, Reset Password Form and Comment Form if there is no one.
• Disable insecure FTP access if there is one.
• Install and activate the Simple History plugin to review access to your website. After 1 or 2 days, review the access information, and possibly block the malicious IP addresses using the Windows Firewall.
• Install, activate and configure Cerber Security plug-in to automatically detect and block the malicious IP addresses.

• Back up database.

  cd /home/ubuntu
  ls
  mysqldump -u root -p -h localhost huybiencomwp > huybiencomwp.sql

• Back up files.

  cd /home/ubuntu
  ls
  sudo zip -r /home/ubuntu/huybien.zip /var/hosting/huybien.com/html

• Download database and files backup.
• Remove the backups.

  sudo rm -rf /home/ubuntu/huybiencomwp.sql
  sudo rm -rf /home/ubuntu/huybien.zip
  ls