To block or success-seo.com just add this lines at the end of your .htaccess file
Code:
## STOP REFERRER SPAM
RewriteCond %{HTTP_REFERER} success\-seo\.com [NC,OR]
RewriteCond %{HTTP_REFERER} semalt\.com [NC,OR]
RewriteCond %{HTTP_REFERER} best\-seo\-solution\.com [NC,OR]
RewriteCond %{HTTP_REFERER} best\-seo\-offer\.com [NC]
RewriteRule .* - [F]
