Disable Trackbacks
When it comes to spam and pingbacks/trackbacks, 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 Cookies For Comments 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.
Kama SpamBlock
Kama Spamblock blocks simple automated comment spam. It is invisible to normal visitors and does not use captchas. The plugin protects the standard WordPress comment endpoint, wp-comments-post.php. It adds a small check to the comment form. Direct requests that skip the form are blocked. This is a basic check, not proof that a person wrote the comment. Bots that load the page and run JavaScript can pass it. Kama Spamblock does not replace a full anti-spam service. It also checks pings and trackbacks for a link back to your site. Even if you are using an external comment system like Disqus, Kama Spamblock can add lightweight protection. Automated requests can be posted directly to the ‘wp-comments-post.php’ file, where the plugin can block basic bots. Simple and effective protection Kama Spamblock combines several small checks that are inexpensive for the site and invisible during normal commenting: The protective field name and its unique code rotate together every four hours. Ten recent pairs remain valid for pages served from full-page cache. Each marker is tied to the specific WordPress post, so a marker copied from another comment form is rejected. The form must remain open for at least three seconds before it can be accepted. Protective fields are added only after interaction with the comment submit button. If a valid comment is blocked, a JavaScript-only retry form preserves the entered data. The retry challenge changes its HTML structure to make basic scraping less reliable. Pingbacks and trackbacks must return a successful HTTP response, non-binary content, and a real backlink. These checks deliberately remain lightweight. A capable bot that loads the page, runs JavaScript, and reproduces normal browser behaviour can still pass them. Using Kama Spamblock with other anti-spam plugins Kama Spamblock can work with a full anti-spam plugin or service. It blocks simple direct spam requests first. The other tool can then check the comments that remain. For example, it can analyse comment text, reputation, or behaviour. The plugins complement each other. For this combination to work as intended: The other plugin should use the standard WordPress comment flow, or check comments after Kama Spamblock allows them. The site must show the standard comment form and allow the plugin’s JavaScript to run. Set the correct ID for the form’s submit button in the plugin settings. Test the setup if another plugin replaces the comment form, uses AJAX, or sends comments to its own endpoint. Kama Spamblock may need extra integration, or it may not check those comments.
