I’ve started a war with comment spam. I will take any measures to keep them away from me. Here is a link
to all the available resources.
Here is AuthImage plugin to deter spam.
First, I changed the name of wp-comments-post.php to another name and made the corresponding adjustment in wp-comments.php.
Second, I installed the plugin of authimage
I think these 2 measures can effectively deter comment spams.