How to protect the site from trojans (backdoors mainly) with third-party services?

Question

Malware

Colleagues, this is the second time the site has been hacked into Joomla. What are the services or add-ons for protection.
I know RSFirewall! but on thematic forums they write that it is only an illusion of protection.
I know about BotGuard, but we have shared hosting, he won't join it.
What else?

Answer 1

https://www.nginx.com/products/nginx-waf/

Answer 2

Maybe it will be enough to update Joomla? :-) Virtual servers cost from 100 rubles per month, move to VPS and install the software and versions you see fit.