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 »

List All Files and Folders Recursively via Terminal

From time to time I have occasion to generate a list all WordPress files or similar. As I’m not an expert in Terminal, it took awhile to figure out the magic recipe.. now having collected some useful commands, I want to post ‘em for future reference. 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 »

expose_php, Easter Eggs, and .htaccess

A reader recently brought to my attention a reported vulnerability on servers running PHP. 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. It only takes a moment to disable the easter-egg information, should you decide to do so. Continue reading »

PayPal Phishing Spam

Just a heads up to anyone else getting the occasional PayPal phishing spam.. Usually it’s pretty easy to spot one of those crafty phishing emails, just hover over any links before clicking to view the real URL in the status bar. You know, the link says something like, “click here to restore your PayPal account,” but you know that’s garbage and could easily prove it by checking the actual link URL, which is usually something completely bonkers, like: Continue reading »

10 Characters for Your WordPress Blacklist

[ Screenshot: Comment Spam in Moderation ]

Quick WordPress tip for easily and quietly blocking a ton of comment spam. Akismet and other programs are good at catching most spam, but every now and then a bunch of weird, foreign-language spam will sneak past the filters and post live to your site. Here’s a good example of the kind of stuff that’s easy to block: Continue reading »

2010 User-Agent Blacklist

The 2010 User-Agent Blacklist blocks hundreds of bad bots while ensuring open-access for the major search engines: Google, Bing, Ask, Yahoo, et al. Blocking bad user-agents is an effective addition to any security strategy. It works like this: your site is getting hammered by rogue bots that waste valuable server resources and bandwidth. So you grab a copy of the 2010 UA Blacklist from Perishable Press, include it in your site’s root .htaccess file, and enjoy better security and performance. […] Continue reading »

Best Method for Email Obfuscation?

Awhile ago, Silvan Mühlemann conducted a 1.5 year experiment whereby different approaches to email obfuscation were tested for effectiveness. Nine different methods were implemented, with each test account receiving anywhere from 1800 to zero spam emails. Here is an excerpt from the article: When displaying an e-mail address on a website you obviously want to obfuscate it to avoid it getting harvested by spammers. But which obfuscation method is the best one? I drove a test to find out. After […] Continue reading »

2010 IP Blacklist

Over the course of each year, I blacklist a considerable number of individual IP addresses. Every day, Perishable Press is hit with countless numbers of spammers, scrapers, crackers and all sorts of other hapless turds. Weekly examinations of my site’s error logs enable me to filter through the chaff and cherry-pick only the most heinous, nefarious attackers for blacklisting. Minor offenses are generally dismissed, but the evil bastards that insist on wasting resources running redundant automated scripts are immediately investigated […] Continue reading »

Is it Secret? Is it Safe?

Whenever I find myself working with PHP or messing around with server settings, I nearly always create a phpinfo.php file and place it in the root directory of whatever domain I happen to be working on. These types of informational files employ PHP’s handy phpinfo() function to display a concise summary of all of your server’s variables, which may then be referenced for debugging purposes, bragging rights, and so on. While this sort of thing is normally okay, I frequently […] Continue reading »

How to Protect Your Site Against Content Thieves (and Other Scumbags)

Stolen content is the bane of every blogger who provides a publicly available RSS feed. By delivering your content via feed, you make it easy for scrapers to assimilate and re-purpose your material on their crap Adsense sites. It’s bad enough that someone would re-post your entire feed without credit, but to use it for cheap money-making schemes is about as pathetic as it gets. If you’re lucky, the bastards may leave all the links intact, so at least you […] Continue reading »

Disable Trace and Track for Better Security

The shared server on which I host Perishable Press was recently scanned by security software that revealed a significant security risk. Namely, the HTTP request methods TRACE and TRACK were found to be enabled on my webserver. The TRACE and TRACK protocols are HTTP methods used in the debugging of webserver connections. Although these methods are useful for legitimate purposes, they may compromise the security of your server by enabling cross-site scripting attacks (XST). By exploiting certain browser vulnerabilities, an […] Continue reading »

HTAccess Password-Protection Tricks

Recently a reader asked about how to password-protect a directory for every specified IP while allowing open access to everyone else. In my article, Stupid htaccess Tricks, I show how to password-protect a directory for every IP except the one specified, but not for the reverse case. In this article, I will demonstrate this technique along with a wide variety of other useful password-protection tricks, including a few from my Stupid htaccess Tricks article. Before getting into the juicy stuff, […] Continue reading »

Associate Any File with Windows Notepad in Five Seconds

In my article, Associate Extensionless Files with Notepad, I explain how to navigate the labyrinthine maze of Windows dialogue menus to assign Microsoft’s Notepad text editor as the opening application for files without extensions. In this post, I’ll show you how to associate any file type with any program (including Notepad) in less than five seconds. Ready? Don’t blink, you’ll miss it.. ;) Continue reading »

Secure Visitor Posting for WordPress

Normally, when visitors post a comment to your site, specific types of client data are associated with the request. Commonly, a client will provide a user agent, a referrer, and a host header. When any of these variables is absent, there is good reason to suspect foul play. For example, virtually all browsers provide some sort of user-agent name to identify themselves. Conversely, malicious scripts directly posting spam and other payloads to your site frequently operate without specifying a user […] Continue reading »

How to Take DVD/Video Screenshots on Windows

Taking screenshots of DVD, MPEG, AVI, and other video on Windows machines requires a couple of extra steps. A normal screenshot is easy enough to capture by pressing the “Print Screen” button on your keyboard. To capture a screenshot of video display, however, you need to disable hardware acceleration to make it work. To do this on Windows machines, go to your Desktop properties and click on the Settings tab. Click on the Advanced button and then on the Troubleshooting […] Continue reading »

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