Like many of the websites I manage, this block sees quite a bit malicious traffic from Russia and China.

Assuming that you are using CloudFlare. Here is how to add firewall rules to block these countries from accessing your website.

First go to Firewall and Create a Firewall Rule

Next name your rule.
Select Country, Value China, And, Country, Value Russian Federation, Action Block, and Click Deploy.

You now are blocking Russia and China from accessing your WordPress Site. After a couple days check back to Cloudflare under the Firewall settings and you can see how effective your rules are by looking at the activity over the last 24hr.