Disinfect malware and install antivirus on contracted server

I have contracted a Hostgator server partition, the classic Baby plan, multidomain. The Cpanel has a free antivirus for users; however, Hostgator decided to remove it from the dashboard and charge for it. I pay them additionally for that service, the classic and the premium, but still, it’s not good.

I have several domains and subdomains with malware, it’s only 700 mb of information to disinfect.

The job is first to disinfect the server, if possible leave another more effective antivirus installed. Also, suggestions to protect the information from future attacks. They manage their firewall, but it seems that it is not good either.

If it is deemed necessary to purchase antivirus software for servers, I would pay for it separately.

I give you the Cpanel installation link
https://docs.cpanel.net/installation-guide/install/

https://docs.cpanel.net/knowledge-base/third-party/how-to-install-imunifyav/

Also, in the attach I send screenshots to see installation privileges. Someone told me it helps, but it was NOT permission level enough