The following snippet added to your htaccess file will block referral spam from accessing your site.
# Block fake traffic RewriteEngine on Options +FollowSymlinks RewriteCond %{HTTP_REFERER} ^https?://([^.]+.)*savetubevideo.com [NC,OR] RewriteCond %{HTTP_REFERER} ^https?://([^.]+.)*srecorder.com [NC,OR] RewriteCond %{HTTP_REFERER} ^https?://([^.]+.)*semalt.com [NC,OR] RewriteCond %{HTTP_REFERER} ^https?://([^.]+.)*kambasoft.com [NC,OR] RewriteCond %{HTTP_REFERER} ^https?://([^.]+.)*buttons-for-website.com [NC,OR] RewriteCond %{HTTP_REFERER} ^https?://([^.]+.)*savetubevideo.com [NC,OR] RewriteCond %{HTTP_REFERER} ^https?://([^.]+.)*seoanalyses.com [NC,OR] RewriteCond %{HTTP_REFERER} ^https?://([^.]+.)*darodar.com [NC,OR] RewriteCond %{HTTP_REFERER} ^https?://([^.]+.)*ilovevitaly.com [NC,OR] RewriteCond %{HTTP_REFERER} ^https?://([^.]+.)*priceg.com [NC,OR] RewriteCond %{HTTP_REFERER} ^https?://([^.]+.)*blackhatworth.com [NC,OR] RewriteCond %{HTTP_REFERER} ^https?://([^.]+.)*ilovevitaly.co [NC,OR] RewriteCond %{HTTP_REFERER} ^https?://([^.]+.)*srecorder.com [NC,OR] RewriteCond %{HTTP_REFERER} ^https?://([^.]+.)*hulfingtonpost.com [NC,OR] RewriteCond %{HTTP_REFERER} ^https?://([^.]+.)*cenoval.ru [NC,OR] RewriteCond %{HTTP_REFERER} ^https?://([^.]+.)*bestwebsitesawards.com [NC,OR] RewriteRule ^(.*)$ http://semalt.com/ [L]