Trackback ‘link back’ checker

That would be Spam Karma:

https://unknowngenius.com/blog/wordpress/spam-karma/dev/

Actually, now that I think about it, Spam karma doesn’t do that, and no plugin ever should. It is possible and common practice to send a trackback to another blog’s post without linking to it. Blocking trackbacks from blogs that do not link to you would delete some legitimate trackbacks.

Now, you may be getting trackbacks confused with referrers. Referrers are access log entries of visitors from sites which [supposedly] link to you. You may see quite a few referrers from other blogs, but you may also see a few referrers from porn and gambling sites. These porn and gambling sites don’t actually link to you, they send out bots which fake the referrer field. Referrer Karma will check the incoming referrers to see if they actually link to you. If they do, the visitor from the legitimate referrer is allowed entry. If they don’t, the visitor from the faked referrer is denied entry.

You can find Referrer Karma here: https://unknowngenius.com/blog/wordpress/ref-karma/

And you can find information about referrer spam here:
https://codex.www.ads-software.com/Plugins/Spam_Tools#Referrer_Spam
https://codex.www.ads-software.com/Combating_Comment_Spam/Denying_Access#Editing_.htaccess_To_Deny_Access_Referrer_Spammers

That was probably what I was thinking of, thanks!

[EDIT] I now KNOW that RK was the plugin I was thinking of, from this line on its Codex description ‘This criteria includes, whether or not the page returns a 403 (access denied), a 404 (not found), or whether or not your URL was found on the referring page'[/EDIT]

Unfortunately it turns out that I can’t use RK because I don’t have url::fopen on my server, but I have Bad Behaviour already which apparently tackles referrer spam