WordPress Error Fix: “Call to undefined function get_header()”

I’m seeing a big increase in bot attacks targeting theme files directly. First they get the URL to your theme directory. There are numerous ways for a bot to get this information. For example most themes include assets like CSS and JavaScript files, and the link includes the full URL. So then once they have the theme URL, bad bots will make direct requests for well-known theme template files, like index.php and header.php. Requesting template files directly may reveal possible […] Continue reading »

Ultimate Comment Blacklist for WordPress: How to Stop Spam Without Plugins

[ WordPress Ultimate Comment Blacklist ]

How do YOU stop comment spam? If you’re like a lot of WordPress users, you just grab another plugin or two and call it good. I mean after all, plugins like Akismet work great at stopping spam. The only downside is that, well, you’re relying on another plugin. And that’s fine for folks who just wanna “get ’er done”, although each active plugin requires additional maintenance and server resources. Continue reading »

Automatic IP Blacklist

Recently a reader going by the name of Rock Star sent me a cool little PHP script that automatically updates your site’s .htaccess with a current list of bad IP addresses. This is useful because it gives you better “real time” protection against attacks and malicious requests. This tutorial shares the code and explains how to implement in two easy steps. Continue reading »

Difference between mod_alias and mod_rewrite

Most of the redirect techniques provided in my stupid .htaccess tricks article all use Apache’s alias module, mod_alias. You can also use mod_rewrite to redirect URLs. The main difference is that, with mod_alias, the server is responding to the client request with a redirect, so the client immediately is sent to the new location. Conversely, with mod_rewrite, the server simply returns the new content, so the client is not actually redirected anywhere. This makes mod_rewrite more advantageous because it happens […] Continue reading »

404 Fix: Block Nuisance Requests for Non-Existent Files

[ Han Solo shutting up C-3PO in Empire Strikes Back ]

As I’ve written before, blocking nuisance requests can help save you money by cutting down on wasted server resources, memory, and so forth. It also saves you time, as your server access and error logs won’t be full of nuisance request spam. So you will have more resources and time for things that matter, like running your business, helping customers, improving code, etc. So to continue the proud tradition of blocking malicious traffic, this post builds upon previous blocking techniques […] Continue reading »

Examples of Nested Encoding

Typically malicious scans use some sort of encoding to obscure their payloads. For example, instead of injecting a literal script, the attacker will run it through a PHP encoding function such as base64_encode(), utf8_encode(), or urlencode(). So if and when you need to decode some discovered payload, you can use whichever decoding function will do the job. For example, base64_decode(), utf8_decode(), or urldecode(). Sounds straightforward, but let’s dig a little deeper.. Continue reading »

WordPress .htaccess file

The WordPress core uses .htaccess for two things: Permalinks and Multisite. This means that .htaccess is only required if you have enabled either of these features. Otherwise, .htaccess is entirely optional for default WordPress installations. Beyond the WP core, many plugins also use the .htaccess file for custom directives involving rewrites, redirects, custom headers, file compression, and much more. In many cases, such plugins add their .htaccess rules to your .htaccess file automatically, behind the scenes. Continue reading »

.htaccess Cleanup

Once again I am cleaning up my sites’ .htaccess files. I do this from time to time to remove old redirects, refresh blacklists, and update security and SEO-related directives. It’s tedious work, but the performance and security benefits make it all worthwhile. This post shares some of the techniques that were added, removed, or replaced from .htaccess, and explains the reasoning behind each decision. I do this for the sake of reference, and hopefully it will give you some ideas […] Continue reading »

Stop WordPress from modifying .htaccess

By default, depending on file permissions, WordPress automatically will modify the contents of your site’s .htaccess file. It does this on several occasions, adding and/or updating the rewrite rules required for WP’s permalink functionality. This post explains how this works, why it can be dangerous, and how to stop it from happening. Continue reading »

Lynda.com Course: Developing Secure WordPress Sites

[ WordPress: Developing Secure WordPress Sites ]

After months of preparation and production, my new video course on developing secure WordPress sites is now available at Lynda.com. This is my second video course on securing WordPress; the first one was originally launched in 2011 and remained in Lynda’s library for over five years. I received a lot of great feedback on the course, and so I jumped on the opportunity to do another one. If there is one thing that I enjoy doing, it’s helping people with […] Continue reading »

Stop User Enumeration in WordPress

This tutorial explains how to block user-enumeration scans in WordPress. As explained in greater depth here, user enumeration happens when some malicious script scans a WordPress site for user data by requesting numerical user IDs. For example, requests for author=1 through some number, say, author=1000, may reveal the usernames for all associated users. With a simple enumeration script, an attacker can scan your site and obtain a list of login names in a matter of seconds. Continue reading »

Stop RSSing.com from Framing Your Content

[ RSSing.com Removal Request or Whatever ]

This quick post explains how to stop the notorious site scrapers, RSSing.com, from stealing your content. In fact, this technique can be used to stop virtually any site that uses HTML frames to scrape your pages. Once again, the solution is one line of .htaccess to the rescue. Continue reading »

Use Strong Usernames for Better Security

Image courtesy of eChunks.com Here is a quick security tip for people using popular apps on the Web. That is, apps like WordPress that may be widely used and targeted by bad actors and/or automated scripts. It’s all about adding another layer of security by hardening admin-level usernames.. Every now and then, I get an email letting me know that someone has requested a password reset for one of my admin-level WordPress accounts. Usually, the email notifications are sent directly […] Continue reading »

WordPress Plugin: Blackhole for Bad Bots

Image Courtesy NASA/JPL-Caltech. Update: Pro version now available! Check out Blackhole Pro » Finally translated my Blackhole Spider Trap into a FREE WordPress plugin. It’s fun, fast, flexible, and works silently behind the scenes to protect your WordPress-powered site from malicious bots. Here are some of the features: Continue reading »

What to do when your site gets hacked

Over the years, my sites have been hacked numerous times. Each hacking event was somewhat of a miserable experience at first, but ultimately educational and even enlightening. I’m not going to say that getting hacked was the best thing that ever happened to me, but it certainly wasn’t the end of the world. In this post, I want to share some important steps to take and things to keep in mind if and when you discover that your site has […] Continue reading »

Protect Against Malicious POST Requests

Whether you like it or not, there are scripts and bots out there hammering away at your sites with endless HTTP “POST” requests. POST requests are sort of the opposite of GET requests. Instead of getting some resource or file from the server, data is being posted or sent to it. To illustrate, normal surfing around the Web involves your browser making series of GET requests for all the resources required for each web page. HTML, JavaScript, CSS, images, et […] Continue reading »

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