My website is not loading because of some infected plugins

Hi,
My web host has blocked some files on my server so I cannot log in to my dashboard. When asked they provided the list of infected files on my server which are these:
——-
/public_html/wp-content/plugins/custom-contact-forms/import/1408061913ccf.sql.php
/public_html/wp-content/plugins/custom-contact-forms/import/1408409739ccf.sql.php
/public_html/wp-content/plugins/custom-contact-forms/import/1408409842ccf.sql.php
/public_html/wp-content/plugins/custom-contact-forms/import/1409169538ccf.sql.php
/public_html/wp-content/plugins/custom-contact-forms/import/1408010569ccf.sql.php
/public_html/wp-content/plugins/wordpress-seo/k53ns3.php
——-

I removed these files from the plugins folder.
I also downloaded a fresh WordPress SEO folder from www.ads-software.com plugins directory.
I notice that there are a few files on my server inside the WordPress SEO folder which are not there in the downloaded folder, which are these;

codesniffer.xml
composer.json
Gruntfile.js
package.json
phpunit.xml

I am confused if I should remove these files or not.
Please help me.

Thanks in advance for your support.