2013 User Agent Blacklist

The 2013 User Agent Blacklist blocks hundreds of the worst bots while ensuring open-access for normal traffic, major search engines (Google, Bing, et al), good browsers (Chrome, Firefox, Opera, et al), and everyone else. Compared to blocking threats by IP, blocking by user-agent is more effective as a general security strategy. Although it’s trivial to spoof any user agent, many bad requests continue to report user-agent strings that are known to be associated with malicious activity. For example, the notorious “httrack” user agent has been widely blocked since at least 2007, yet it continues to plague sites to this day. […] Read more »

2013 IP Blacklist

When time allows, I like to post my collections of the worst IP addresses for the current year. Certainly, there are pros and cons to using an IP blacklist. In general, IPs are easily spoofed, change frequently, and are therefore unreliable as a general security strategy. But as a short-term solution, IP blacklists serve as an excellent method for dealing with specific and/or ongoing threats and attacks. Read more »

5G Blacklist 2013

Update: Check out the new and improved 6G Firewall 2016! Following up on much feedback (and this post), here is an update for the 5G Blacklist for 2013. As explained in the 2012 article (and elsewhere), the 5G Blacklist helps reduce the number of malicious URL requests that hit your website. It’s one of many ways to improve the security of your site and protect against evil exploits, bad requests, and other nefarious garbage. If your site runs on Apache and you’re familiar with .htaccess, the 5G is an effective way to secure your site against malicious HTTP activity. Read more »

Protection for WordPress Pingback Vulnerability

It was recently reported about a WordPress Pingback Vulnerability, whereby an attacker has four potential ways to cause harm via xmlrpc.php, which is the file included in WordPress for XML-RPC Support (e.g., “pingbacks”). In this post, I offer a simple .htaccess technique to lock things down and protect against any meddling via the xmlrpc.php file. Note: this technique is only recommended if you aren’t using XML-RPC for anything (e.g., pingbacks, Blogger, MovableType, etc.). Update: Check out the alternate method to whitelist specific IPs while protecting against threats. Read more »

Printed .htaccess books

After launching my new book .htaccess made easy back in September, I wanted to allow time to fix any errors or typos before sending the book to the printers. After a couple of months, I had updated the book three times with better code, new techniques, and design improvements. After a few final steps to optimize for print format, the books were ordered, printed and delivered fresh on Christmas Eve :) So to celebrate the event, all printed .htaccess books are on sale for $10 off, and all PDFs are on sale for $5 off. Read more »

Blacklist Candidate 2012-11-13: Evil Scanner Edition

It’s been awhile since I’ve posted one of my Blacklist Candidate series articles. It’s always fun for me to talk (or write) about security related issues, especially when a quick slab of .htaccess can be used to take care of business. And that’s exactly what we have in this edition of the series, where I’m pleased to bring you Blacklist Candidate Number 2012-11-13: the “evil” scanner. Instead of scanning your site, collecting data, and moving on, Mr. 2012-11-13 continues to scan the same sites for the exact same set of files. And by “continues” I mean over and over and […] Read more »

expose_php, Easter Eggs, and .htaccess

A reader recently brought to my attention a reported vulnerability on servers running PHP (404 link removed 2016/02/22). It’s been known about for eons, but it’s new to me and it involves easter eggs in PHP so I thought it would be fun to share a quick post about what it is and how to prevent leakage of sensitive information about your server. Read more »

Protect Against Brute-force/Proxy Login Attacks

For the past week, I’ve been monitoring activity from a set of IP addresses involved with brute-force login attacks. Brute-force login attacks involve systematic guessing of passwords using various common usernames such as “admin” and “username”. So for example, an attack will target an array of sites, use “admin” as the username, and then make numerous attempts at “guessing” your password. And to obfuscate their malicious activity, the attack is executed from multiple IP addresses, either via proxy or possibly a botnet. Read more »

New Book!

I’m proud to announce the launch of my new book on .htaccess, titled .htaccess made easy. It’s a book I’ve been wanting to write for years, since first getting hooked on .htaccess way back in 2006. Since then, I’ve learned a lot about .htaccess, Apache, security, and web-design in general — with many articles on the topic published here at Perishable Press and elsewhere on the Web. Everyone kept inspiring me to bring it all together and write a book on the subject, and so WHOOOP here it is! Read more »

Prevent Duplicate Content in cPanel

In this guest-post, Jon Brown shares a solution to the age-old problem of preventing duplicate content from addon-domains in cPanel. Jon explains the issue and shares his methodology in crafting an elegant solution applied via .htaccess. If you’re using cPanel and want to improve your SEO, this will help. Here is the table of contents: Read more »

6G Beta

Update: Check out the new and improved 6G Firewall 2016! Since releasing the 5G Blacklist earlier this year, malicious server scans and bad requests have surged with more novel attacks than I’ve seen since first getting into this stuff six years ago. In other words, now is the time to beef up security and lock things down. If you’re into monitoring your server and knowing your traffic, you may be observing the same recent spike in malicious activity. In response to these attacks, I’ve been secretly working on the next generation of G-series blacklist, the inevitable 6G Firewall. Read more »

Blank Space / Whitespace Character for .htaccess

Working on the next version of the G-Series Blacklist, I needed a way to match a wide variety of UTF-8-encoded (hex) character strings. Those familiar with their site’s traffic will recognize this particular type of URI request string, which is typically associated with malicious server scanning, exploits, and other malicious behavior. As I explain in this post, pattern-matching and blocking the blank-space, or whitespace character in URL-requests is an effective way to improve the security of your website. Read more »

Case-Insensitive RedirectMatch

Cool trick that you may not have known about.. it’s possible to get case-insensitive matching with the powerful RedirectMatch directive. Normally, you would just write your redirect as something like this: Read more »

WordPress Add-on for 5G Blacklist

Ill requests and malicious scans have been spiking recently, to the point where server performance was really taking a hit. One scan in particular hammered the server with thousands of bad requests in just a few minutes. There are people out there with strong scripts and small minds that are constantly scanning sites for vulnerabilities, and much of what I’ve seen is aimed primarily at WordPress. Read more »

Redirect WordPress Date Archives with .htaccess

Restructuring a WordPress website may involve removing the subdomain from URLs/permalinks. For example, I recently removed the original WP-install subdirectory from Perishable Press to simplify site structure and optimize WordPress permalinks. There are PHP scripts and WP plugins that might work for this, but in most cases .htaccess is optimal when changing URL structure and redirecting traffic. Here’s a quick example to help visualize the concept: Read more »

5G Blacklist 2012

Update: Check out the new and improved 6G Firewall 2016! The 5G Blacklist helps reduce the number of malicious URL requests that hit your website. It’s one of many ways to improve the security of your site and protect against evil exploits, bad requests, and other nefarious garbage. After extensive beta testing, the 5G Blacklist/Firewall is solid and ready to help secure sites hosted on Apache servers. In addition to beta testing for the 5G, this is the 5th major update of my “G”-series blacklists. Here is a quick overview of its evolution: Read more »

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