Please read the link I posted.
1. Make a list of all the plugins and themes you have installed.
2. Via FTP or your hosting control panel, delete the directories
2a) wp-admin
2b) wp-includes
2c) wp-content/plugins
2d( wp-content/themes
2e) all PHP files in the root of your site *except* wp-config.php
3. Download a fresh copy of WordPress and unzip locally
4. Via FTP, upload the contents of the “wordpress”directory you got when you unzipped.
5. Login to your site and re-install your plugins and themes
6. Via FTP or your hosting control panel, delete the file “.htaccess” in the root of your site. Go to Settings->Permalinks and click “save” to recreate it.
7. Install the plugin “wordfence”. Set it to do a “high sensitivity” scan and scan your site to see if you got it all.