Alex Mills

When it comes to spam and <a href="https://codex.wordpress.org/Introduction_to_Blogging#Pingbacks" rel="nofollow ugc">pingbacks</a>/<a href="https://codex.wordpress.org/Introduction_to_Blogging#Trackbacks" rel="nofollow ugc">trackbacks</a>, the vast majority by far is via trackbacks rather than pingbacks. Very, very few people use trackbacks for legitimate uses anymore (I’ve gotten less than 5 in the last 8 months) as WordPress, etc. all use pingbacks now as their primary ping method.
I had already installed <a href="http://ocaoimh.ie/cookies-for-comments/" rel="nofollow ugc">Cookies For Comments</a> which successfully stops most spam comments but I still had to deal with the tons of trackback spam. So, I wrote this plugin.
It will disable new trackbacks across your site, both legitimate and spam. However since very few people use trackbacks legitimately, this combined with Cookies For Comments should cut your spam down to next to zero.
Why should I use this plugin over one of those trackback validator plugins?
Most non-Akismet style anti-trackback spam plugins work by connecting to the URL that sent the trackback and looking for a link to your blog. The problem with this is that many spammers actually post links to your blog in their spam posts rendering those types of plugins useless. Even those that check the IP address to make sure it matches are beaten by spam blogs (aka splogs).
In the end it’s up to you what to use for anti-spam, but I personally use Cookies For Comments, this plugin, and then Akismet to catch anything that makes it through.

Disable Trackbacks

Globally disables trackbacks to cut down on spam. Very, very few people legitimately use trackbacks and spammers love them, so it's worthy tradeo …

mihai

This plugin will modify the links on pingbacks (and trackbacks) to remove the 
“external nofollow” for links to your own blog.
More info:
<ul>
<li><a href="http://patchlog.com/follow-self-pings/" rel="nofollow ugc">Follow Self Pings plugin</a>.</li>
<li>Check out the other <a href="http://patchlog.com/wordpress/" rel="nofollow ugc">WordPress plugins</a> by the same author.</li>
</ul>

Disable Trackbacks vs Follow Self Pings