I’ve noticed and so have others about a problem while posting comments on this blog.

IE throws up a Page Cannot Displayed error and Firefox asks you to download the PHP file.

I’m still clueless as to what could be the exact problem with this and so I’ve decided to test Akismet instead of SK2 for a while in the process of isolating and eliminating the error.

I don’t believe this problem to be because of PHP, because I can make posts perfectly with a lot more data than the comments.

My next step after this is to deactivate the Math Plugin to see if that could a cause. I might switch back to Peter’s Antispam with the CAPTCHA as well.

Any one have any ideas about what could be causing this problem?

I noticed today that WP-Cache wasn’t cleaning the cache whenever a new comment was posted.

I remembered that Everton had the same problem earlier and he had found a solution to it.

This didn’t seem to be an isolated case and it can be pinned down to Spam Karma 2 and WP-Cache not playing well together.

However, Priv has a solution in the form of a SK2 Plugin.

1. Simply download the plugin and dump it in your sk2_plugins folder. You’ll find this in the main SK2 folder.
2. Goto Options > Spam Karma 2 once to make sure SK2 recognizes the same. It also helps you verify if it has been setup correctly.
3. Flush the Cache via Options > WP-Cache

I’m going to evaluate to see if this solves the problem. If you’re using SK2 and WP-Cache, then I suggest getting this installed.
If you have already done so, give me your feedback on the same.

Following Thilak’s results, I installed Peter’s Custom Anti-Spam Image Plugin for WordPress to test.

I’m much against the idea of using Captcha for my blog, because of the problems with accessibility. However, of late I have been getting a lot of spam.

Even though Bad Behavior has blocked 10000+ access attempts in the last seven days, a good portion of spam has been getting through.

This has been caughty by Spam Karma 2 successfully. However, they are still getting through and still consuming bandwidth.

Hence, I felt the need of installing Peter’s plugin. Thilak has found the amount of spam being blocked reducing from 1000 to around 5 a day.

I will be monitoring this for the next few days. The plugin is easy to use and install. The image is also clearly visible, so you shouldn’t face any problems with reading it.

If you do face any problems please email me, so that I can take necessary action.

I had to make some changes to the code to make it XHTML 1.1 compatible. Will write detailed installation instructions tomorrow.

Blog spam is something that every blogger fears. Spam appears in different forms. It can vary from trackback or pingback spam, comment spam, deliberate harsh comments to email harvesting and spam resulting from it.

Spam cannot be stopped. But by following a few good steps you can protect yourself from it.
This tutorial will teach you how to protect your WordPress blog from spam.

Before they hit you

This should be the first thing you do to prevent spam. I have found two very effective plugins which do the job very well. One is Bad Behavior and the other is Referrer Karma. I am currently using Bad Behavior on my blog. Optionally, you can add my Bad Behavior Stats Plugin to display the number of blocked attempts on your blog.

Yet another step to prevent bad bots and spam is to use your .htaccess file to block them. JavaScriptKit has a good tutorial on Blocking bad bots and site rippers (aka offline browsers). Simply copy-paste the code they give you into your .htaccess file and your ready.

As and when they hit you

Unfortunately the steps above alone will not protect you completely. Though the plugins above do an excellent job, I will admit that spammers are smart and they find a way to get through and you will suddenly see your blog filled with spam comments.

Some spammers do get through the above protection, and then you gotta take another step to protect you.

To prevent this one of the most effective plugins I have found to date is Spam Karma 2. It provides many checks and drastically reduces the amount of comment, trackback and pingback spam.

Once again, though SK2 effectively blocks most of the spam, it does struggle when a spammer personally enters the comment on your blog. On the surface it may appear rather innocent but infact is just another spammer in disguise pointing links to his site. And they rarely appear again on your site.

So, the next thing I did was install the Moderate Plugin for SK2. This plugin will ensure that new posters will land into moderation for your approval. So even if a person gets through Bad Behavior and Spam Karma 2, you can choose whether you want to approve this comment or not.
Remember though for this to effectively work you need to ensure that these two options are checked
1. “An administrator must approve the comment (regardless of any matches below)” (under Options ? Discussion)
2. “Comment author must have a previously approved comment” ( also under Options ? Discussion)

I have found by following the two steps above I have remained spam free for a long time now.

WordPress now comes bundled with an anti-spam plugin called Akismet. Akismet works in a different manner from SK2. Here, when a new comment, trackback, or pingback comes to your blog it is submitted to the Akismet web service which runs hundreds of tests on the comment and returns a thumbs up or thumbs down.

When the plugin catches something as spam it saves it in the database for 15 days in case you want to check it out manually and then automattically deletes it. In the unlikely event something gets incorrectly identified as spam you can correct it and it submits the “false positive” back to Akismet for analysis and improvement of our system. If a spam comment happens to get through and you mark it as spam within WordPress, it does the same thing. Akismet becomes more effective the more you use it.

Using Akismet is very easy. Download the plugin and enter your WordPress.com API Key.

You also have an Akismet Worst Offenders Extension that pre-processes the spam comments and identifies the worst offenders in terms of the domain that?s being advertised, or (perhaps more usefully) the IP Address of the spamming computer.

And to get the best of SK2 and Akismet get hold of the Spam Karm 2 Akismet Plugin. It is a plugin for SK2 that checks the comments with the Akismet web service and thus just making SK2 better.

Yet another plugin is WordPress Hashcash 3.0. Every four hours, your blog picks a random large number (close to 32 bits). Whenever a visitor visits your permalink pages, an ajax call is made which retrieves some javascript. This javascript first decrypts itself, then executes itself again to retrieve the secret value, which it sets in the form. Then it enables the submit button. If a comment does not have this value, it is rejected. If a comment is rejected more than four times, the user is blocked for a specified period of time.

Email Spam

In addition to protecting your blog from comment spam you can take one extra step and protect yourself from email spam from your blog.

The first and most important thing to remember is that putting a mailto: link on your website is an open invitation to spammers.

The best and highly recommended method to let visitors get in touch with you is to use a contact form.
Two popular contact forms for WordPress are PXS Mail and WP-Contact Form.

And if you really want to use your email address on the site then you can make use of either Transpose Email Plugin or EmailShroud Plugin. Both of these use javascript to obfuscate your email address thus prevent email harvesters from getting hold of it.

The former requires the user the manually enter in the code on their blog which is more work but won’t mess up your site.
The latter does this automatically but your links problems could be damaged.

Additional resources:

• Combating Comment Spam
• Spam Tools
• Tackling Comment Spam
• WikiPedia’s Spam in Blog

So what do you do to protect yourself from spam? If you have any suggestions or recommendations please do comment.

If you like this tutorial, please do digg it.

Update: This tutorial is now superceded by A Comprehensive Guide to Protecting Your Blog from Spam.

Comment spam is something every blogger is really really afraid of. Over the past two years that I have been using WordPress this is one problem that I have faced on and off.
I realized that the amount of spam I was receiving was is direct relation to my popularity. (and I wasn’t that know then)

After a lot of experimenting, I have finalized settled down on the following. I’m pretty much spam free for now.

Firstly, get Bad Behavior installed. Bad Behavior blocks spam by checking Referer and a lot of other things the moment it touches your site. It runs silently in the background protecting you. Optionally, you can add my Bad Behavior Stats Plugin to display the number of blocked attempts on your blog.

Next, get hold of Spam Karma 2. Spam Karma is a comment spam protector. It provides many checks and drastically reduces the amount of comment, trackback and pingback spam. Optionally, add Spam Karma 2 Stats.

With just these two plugins installed I had almost zero spam on my site. However, I recommend a few additional things you can do.

Get hold of Moderate Plugin for SK2 and follow the instructions for installing it. This plugin will ensure that new posters will land into moderation for your approval. So even if a person gets through Bad Behavior and Spam Karma 2, you still choose whether you want to approve this comment or not. Believe, I’ve used it many times!

Also, to reduce email spam do not have any mailto: links on your site. Instead make use of contact forms or email plugins like my Transpose Email plugin to protect your email from harvesters.
Two popular contact forms for WordPress are PXS Mail and WP-Contact Form.

Yet another step to prevent bad bots and spam is to use your .htaccess file to block them. Read Blocking bad bots and site rippers (aka offline browsers). Here you will find a nice long list of what you will need to enter into your .htaccess to block the bots and spam.

Additional resources worth checking are:

• Combating Comment Spam
• Spam Tools
• Tackling Comment Spam

I’m pretty much spam free today. So how about you?