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 »

They’re Scanning for Your Backup Files

Just a reminder to keep your backup files offline. Do not store them in any publicly accessible space. It’s just not worth the risk man. And if you’re working online, you should know this already. If not, then continue reading to learn why it’s absolutely mission critical. Continue reading »

Brute-Force Login Drip Attack

I’ve been noticing a new strategy for brute-force login attacks: the slow, incremental “drip” attack. Instead of slamming a login page with hundreds or thousands of brute-force login attempts all within a few minutes, some attackers have been taking a more low-key approach by slowing down the rate of login attempts in order to bypass security measures. The “drip” brute-force attack is extremely annoying, and possibly dangerous if any of your registered users are using weak login credentials. This article […] Continue reading »

How to Block Baidu Bot

A user of my 6G Firewall recently asked how to block the “baidu” bot from accessing their site. This post explains why Baidu is not blocked in 6G and provides a quick .htaccess technique to deny it (or anything claiming to be it) access to your site. Continue reading »

Block D-Bag Database Exploits

Some douchebag has been scanning my sites for a variety of potential database exploits. My sites are secure, so there is no real security threat, but the scans are extremely annoying and waste my server resources. Resources like bandwidth and memory that I would rather use for legitimate visitors. So after collecting some data and experimenting a bit, I wrote a simple .htaccess snippet to block a vast majority of these pathetic database-exploit scans. Continue reading »

6G Firewall

After three years of development, testing, and feedback, I’m pleased to announce the official launch version of the 6G Firewall (aka the 6G Blacklist). This version of the nG Firewall is greatly refined, heavily tested, and better than ever. Fine-tuned to minimize false positives, the 6G Firewall protects your site against a wide variety of malicious URI requests, bad bots, spam referrers, and other attacks. Blocking bad traffic improves site security, reduces server load, and conserves precious resources. The 6G […] Continue reading »

BBQ Firewall – Customize Rules

BBQ Firewall is a lightweight, super-fast plugin that protects your site against a wide range of threats. BBQ checks all incoming traffic and quietly blocks bad requests containing nasty stuff like eval(, base64_, and excessively long request-strings. This is a simple yet solid solution for sites that are unable to use a strong Apache/.htaccess firewall. Continue reading »

Protect Against Humans.txt Query-String Scans

I woke up this morning to the sound of thousands of 404 requests hitting the server. It’s sad that there are kiddies out there who have nothing better to do than buy some pathetic $50 script and then sit there like an imbecile harassing people for hours on end. But alas, that is the world we live in — fortunately it’s less than trivial to block the entire scan with just a few lines of good old .htaccess. Continue reading »

2014 Micro Blacklist

Over the past several months, I’ve assembled a “micro” blacklist to keep some recent threats at bay. Eventually, this will be integrated into the next nG Blacklist, but for now I just wanted to post and share with anyone else who is actively monitoring their server logs and aware of the recent spike in malicious activity. Continue reading »

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 […] Continue reading »

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. Continue reading »

5G Blacklist 2013

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 […] Continue reading »

(Please) Stop Using Unsafe Characters in URLs

Just as there are specifications for designing with CSS, HTML, and JavaScript, there are specifications for working with URIs/URLs. The Internet Engineering Task Force (IETF) clearly defines these specifications in RFC 3986: Uniform Resource Identifier (URI): Generic Syntax. Within that document, there are guidelines regarding which characters may be used safely within URIs. This post summarizes the information, and encourages developers to understand and implement accordingly. Continue reading »

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 […] Continue reading »

BBQ Firewall (Free WordPress Plugin)

BBQ Firewall is a lightweight, super-fast plugin that protects your site against a wide range of threats. BBQ checks all incoming traffic and quietly blocks bad requests containing nasty stuff like eval(, base64_, and excessively long request-strings. This is a simple yet solid solution for sites that are unable to use a strong Apache/.htaccess firewall. Continue reading »

Protect Against Brute-force/Proxy Login Attacks

[ Solomon Grundy of the Legion of Doom ]

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 […] Continue reading »