Block Domains & Subdomains Using .htaccess

By  on  

A large focus of my redesign was improving site speed, and in doing so, I took a look at my site's error_log for the first time in a long time.  I was shocked when I found out that 90% of my site errors were either hacking attempts or hot-linked files from hundreds of different tumblr.com subdomains.  Thousands upon thousands of PHP fatal errors due to lack of memory saw me seeing red pretty quick -- no wonder I was having periodical speed issues!  Luckily this bit of .htaccess code allows me block all of those sites:

<IfModule mod_rewrite.c>
RewriteEngine On
RewriteCond %{HTTP_REFERER} ^https?://([^.]+\.)*tumblr\.com [NC]
RewriteRule .* - [F]
</IfModule>

These days I only see PHP notices in my error_log, and that makes me a very happy man.  I've also noticed less SPAM commenting, so maybe Tumblr is used a SPAM hub too?  Either way, blocking domains and subdomains did the trick for me!

Recent Features

  • By
    CSS @supports

    Feature detection via JavaScript is a client side best practice and for all the right reasons, but unfortunately that same functionality hasn't been available within CSS.  What we end up doing is repeating the same properties multiple times with each browser prefix.  Yuck.  Another thing we...

  • By
    5 HTML5 APIs You Didn&#8217;t Know Existed

    When you say or read "HTML5", you half expect exotic dancers and unicorns to walk into the room to the tune of "I'm Sexy and I Know It."  Can you blame us though?  We watched the fundamental APIs stagnate for so long that a basic feature...

Incredible Demos

  • By
    MooTools Zebra Table Plugin

    I released my first MooTools class over a year ago. It was a really minimalistic approach to zebra tables and a great first class to write. I took some time to update and improve the class. The XHTML You may have as many tables as...

  • By
    CSS Scoped Styles

    There are plenty of awesome new attributes we've gotten during the HTML5 revolution:  placeholder, download, hidden, and more.  Each of these attributes provides us a different level of control over an element on the page, but there's a new element attribute that allows...

Discussion

  1. There are 2 issues with your solution:
    1) If a legit person linked to your blog from their Tumblr blog, people would see a Forbidden message. This is because you have your images under the same domain as the blog. Keeping them on the sub-domain would save your visitors from this.
    2) Security – probably a minor issue, but when you get a Forbidden message from Apache, you also get a path to the content you were forbidden to access. And since you are using WordPress with caching, the message looks as follows:

    Forbidden

    You don't have permission to access /wp-content/w3tc/pgcache//block-domain/_index_search_engines.html_gzip on this server.

    Apache/2.2.3 (CentOS) Server at davidwalsh.name Port 80

    • Thanks for sharing Shimon. Per your points:

      1. If it’s only specific subdomains hurting you, listing them one by one would be best, I agree. In my case, I don’t care if legit Tumblr sites are linking to me. :)

      2. I’ll look into the Forbidden issue — thanks!

  2. Korri

    Wow. blocking anyone comming from tumblr seems pretty extreme to me, you could at least add a RewriteCond to block only static content.

  3. Bob

    Seems like a lot of work, when this doesn’t even require mod_rewrite:

    deny from .tumbler.com

Wrap your code in <pre class="{language}"></pre> tags, link to a GitHub gist, JSFiddle fiddle, or CodePen pen to embed!