Site Lockout Notification

I’ve recently been receiving many emails a day that have one of two subjects: either “File Change Warning” or “Site Lockout Notification.” I am by no means well versed in why this is happening and what to do about it. Here is an example of the information in the “Site Lockout Notification” emails:

Host/User Lockout in Effect Until Reason
Host: 118.24.110.222 2019-03-09 17:07:41 too many attempts to access a file that does not exist

I have received many of these over the past couple months and the Host address is usually different. When I click it to follow the address, it shows that the address is from somewhere in Asia.

I’ve added the various IP addresses to the Ban list but since there is a different address every time, I think it is going to keep happening. What do I do??