Referrer spam also known as log spam or referrer bombing . The technique involves making repeated web site requests using a fake referer URL to the site the spammer wishes to advertise. It improves the site ranking of the spammer


Many website or blog has been hit by  referring spam impersonating bot . Many site uses illegal means to spam websites . you will see referring link of adult site , gambling site and more .

httacess  method
RewriteEngine on
# Options +FollowSymlinks
RewriteCond %{HTTP_REFERER} otherdomain\.com
[NC,OR]
RewriteCond %{HTTP_REFERER} anotherdomain
\.com
RewriteRule .* - [F]

Remember  to put  the two  domain you  want to block  . Unfortunately  blogger don't have httacess  yet .

Blacklist the site
Any site that do this need to be blacklisted .either the url or IP address .

For WordPress
For WordPress  sites  install referrer spam block plugin .This plugin prevents spam referrer
attacks by filtering your incoming
traffic .

To remove them from  your Google  analytics .Filter  all referring spam .For blogger you have to wait for Google to resolve the issues .

for blogger send a feedback on your blogger dashboard that your site is hit by referring spam .