Comment spam is a fact of life if you have a blog.To fight with spammer there are some handy WordPress plugin solution to help you.

[1]. Akismet

Akismet uses a unique algorithm combined with a community-created database to “learn” which comments are comment spam and which are legitimate.This plugin costs $5 a month if you make any money from your site, such as through an affiliate link, ad, or paid service.

[2]. WP-reCAPTCHA

reCAPTCHA is probably the most popular and widely accepted CAPTCHA systems by both end-users and site-owners. It is used by such sites prominent sites as Facebook, Twitter etc.
If the user has trouble reading the CAPTCHA challenge, he or she has the option of requesting a new one. If this does not help, there is also an audio challenge which users may use.

[3]. Stop Spam by referrer requests

Use this .htaccess code on your WordPress default .htaccess file to prevent spammers posting on your blog.

[php] RewriteEngine On
RewriteCond %{REQUEST_METHOD} POST
RewriteCond %{REQUEST_URI} .wp-comments-post.php*
RewriteCond %{HTTP_REFERER} !.*yourblog.com.* [OR] RewriteCond %{HTTP_USER_AGENT} ^$
RewriteRule (.*) ^http://%{REMOTE_ADDR}/$ [R=301,L] [/php]

And replace yourblog.com with your own website URL when you implement it.

Source: How to deny comment posting to no referrer requests

Please leave a comment below if you wnat to share more 🙂