WordPress Error (Malware Infection & WordPress Site Quarantined)

Please, I received an email from my web host with the above information:

WordPress Toolkit was not able to finish running an operation on this site in 60 seconds, so the operation was terminated. This could mean that your WordPress installation might be infected with malware. Check the wp-config.php file of the installation for potential malware code or run an anti-virus scan. If you cannot find any traces of malware, try running the operation again later.

Then when I debug my WordPress site, I got this:

Fatal error: Uncaught Error: Call to undefined function _wp_http_get_object() in /var/www/vhosts/expandgh.com/httpdocs/wp-includes/http.php:180 Stack trace: #0 /var/www/vhosts/expandgh.com/httpdocs/wp-includes/cron.php(729): wp_remote_post() #1 /var/www/vhosts/expandgh.com/httpdocs/wp-includes/cron.php(774): spawn_cron() #2 /var/www/vhosts/expandgh.com/httpdocs/wp-includes/class-wp-hook.php(287): wp_cron() #3 /var/www/vhosts/expandgh.com/httpdocs/wp-includes/class-wp-hook.php(311): WP_Hook->apply_filters() #4 /var/www/vhosts/expandgh.com/httpdocs/wp-includes/plugin.php(478): WP_Hook->do_action() #5 /var/www/vhosts/expandgh.com/httpdocs/wp-settings.php(545): do_action() #6 /var/www/vhosts/expandgh.com/httpdocs/wp-config.php(89): require_once(‘/var/www/vhosts…’) #7 /var/www/vhosts/expandgh.com/httpdocs/wp-load.php(37): require_once(‘/var/www/vhosts…’) #8 /var/www/vhosts/expandgh.com/httpdocs/wp-blog-header.php(13): require_once(‘/var/www/vhosts…’) #9 /var/www/vhosts/expandgh.com/httpdocs/index.php(505): require(‘/var/ in /var/www/vhosts/expandgh.com/httpdocs/wp-includes/http.php on line 180
There has been a critical error on your website.

I notice that all the plugins are not showing the WordPress dashboard.
Also, all the plugins have been automatically deactivated.
Again, the site has been quarantined by the web host.
I have also deactivated the plugins but it doesn’t solve any problem.

I have run a scan…using the software on the host… yet the issue was not resolved.
Please, if it is a malware infection, can anyone help?

The page I need help with: [log in to see the link]