Sucuri CloudProxy WAF
Traffic filtering (blocking malicious requests)
Virtual patching
Virtual hardening
Spam and bots blocking
WAF (Web application firewall) - To prevent SQL injections, XSS, RFI, etc)
IDS/IPS (Intrusion prevention system)
Extended access control (white listing of IPs allowed to go to the admin pages)
OSSEC HIDS (Full log analysis and traffic monitoring)
Improved performance and caching
Fully managed. You just need to switch the DNS of your site and we take care of the rest.
You can read more about some of the features here: http://cloudproxy.sucuri.net
Once enabled, it will protect your site against malware infections and reinfections and all sorts of attacks.