There are tons of WordPress security plugin, but there is none which will serve 100% of your purpose. So, depends on your purpose you have to use multiple plugin but, remind that you have to choose security plugin very carefully.
WordFence Security Plugin and, Firewall is one of the best plugin available, you can scan malware for free and harden htaccess, setup a lightweight firewall without any payment or, cost. It provides good security for WordPress sites. Though its a bit heavy plugin but its worth it.
Sucuri Security Plugin is another best WordPress Security plugin you can use alongside WordFence, you can scan malware and, harden security.