- 1 Introduction
- 2 Audience
- 3 Terminology
- 4 Prerequisites
- 5 The user.js file
- 6 Add-on configuration
- 7 Securing DNS traffic
- 8 Testing your configuration
- 9 Troubleshooting
- 10 Firefox add-ons used in this guide
- 11 Further reading on 12bytes.org
- 12 References and resources
- 13 Revision history
See the revision history at the end of this document for a list of changes.
Many of us are aware of the immense threats to our privacy and security posed by a plethora of technology corporations, governments and malicious hackers, some of which often go to great lengths to monitor our communications and web browsing habits. Governments and their “intelligence” apparatuses not only spy on each other, but on the citizenry as well and they leverage the services of many mega-corporations to do so, including Google, Facebook, Verizon, Comcast, Amdocs and countless others, many of which most of us have probably never heard of. While this data may be used for relatively benign purposes, such as displaying ads in our web browser, all too often the intentions are far more sinister and invasive. Much of what Edward Snowden has brought to the table is not new at all, but it seems the information has been presented in a way that has captured the attention of much of the public, prompting those who value their privacy to seek ways to mitigate the threats. The goal of this guide is to help the reader to thwart some of the efforts to track and profile us as we surf our way around the World Wide Web.
For many of us, our web browser is the primary interface we use to explore the digital world and it is therefore necessary for any privacy conscious individual to consider what information our web browsers are sending and receiving and how that information can be used to track our on-line activities and profile us. Only then can we take action to circumvent some of these threats.
Contrary to the statements made in The Mozilla Manifesto, it is my opinion that the non-profit, multi-million dollar Mozilla Foundation is hardly concerned with the privacy of its software audience, particularly when considering its flagship product, the Firefox web browser. This is readily apparent when one considers the array of ethically challenged multinationals which Mozilla has chosen to partner with, including Google, Yahoo, Microsoft, Telefónica, LG Electronics, Sony, Verizon, Cisco and others. Even the now defunct Firefox Pocket service was tied to a 3rd party company and it seems more “features” are being added with each iteration of the browser. Google Chrome is no better and Internet Explorer isn’t worth the effort required to express an opinion.
That being said, i think Firefox is still a good product in many ways and it is certainly one of the most versatile and hackable mainstream web browsers going. Because it is open source and wide open to customization, i believe the Gecko family of browsers are good candidates for those who wish to reduce their exposure to privacy and security threats. The folks behind the Tor Project seem to think so as well since Firefox is included in their Tor Browser Bundle, though i suspect possibly not for much longer.
This guide is intended for those who are somewhat technically inclined, or are at least willing to learn, and who wish to reduce the threats to their privacy while enhancing browser security and performance. We will attempt to accomplish these goals while maintaining a reasonably carefree web browsing experience which means there will be some trade-offs between security and privacy for ease of use, but you can always adjust to suit your particular needs. This guide is not intended as a complete solution for those whose well-being depends on anonymity (whistle-blowers, etc.) or who require secure methods of transmitting data (journalists, etc.), though it may be a worthy supplement to more specific information. This guide is, a), a work in progress and b), not authoritative since i do not claim to be an authority on Firefox, Internet security or digital privacy. There are simply too many technologies, options and attack vectors for me to comprehend in something as incredibly complex as the modern web browser.
Though this guide is centered around Firefox, it should also be useful to users of other Gecko-based programs, including the SeaMonkey and Iceweasel browsers, as well as the Mozilla Thunderbird email client.
The Mozilla Firefox browser is based on the Gecko layout engine and, as with any mainstream browser, it is a very complex beast consisting of millions of lines of code and hundreds of configuration options, many of which are interlinked, obscure, or even completely hidden. Change a few settings without knowing what you’re doing and things can go south pretty quick. Poorly coded add-ons can compound the problem, especially when they conflict with one another. Here we will attempt to accomplish our goals in an efficient manner with a minimal dependency upon 3rd party add-ons.
There is a huge selection of Firefox add-ons for tweaking privacy and security, some of the most popular of which are Adblock Plus and it’s derivatives, NoScript, Flashblock, Ghostery, Web of Trust, BetterPrivacy, Lightbeam, Disconnect, Self-Destructing Cookies, Cookies Manager+, Request Policy, Policeman, Bluhell Firewall, RefControl, Smart Referer, HTTPS Everywhere and many, many others. With some possible exceptions, we won’t be using any of these, yet will retain most of the important functionality of most of them with just two add-ons along with a plethora of changes to our Firefox configuration.
A bit of a trade-off should be expected as we tighten up on security and privacy insomuch as some websites will cease to function properly until the settings for the affected sites are adjusted. Anyone who has used a content filter such as NoScript will understand that certain resources must be allowed for many websites to function in a way that is acceptable to us. As with NoScript however, the process of allowing these resources with the add-ons suggested herein, usually requires little more than a mouse click or two and a page refresh. Furthermore, once we have visited all of our favorite websites and made the necessary adjustments, our workload will be greatly reduced. Nevertheless, you should be prepared to put a little more effort into your web browsing experience in general and expect the occasional hard-case which will require more fiddling than usual to get a particular site to function properly. The pay-off however is a much cleaner, faster web that is less able to track and profile us as well as a hardened browser that is more resistant to attack.
AMO: The Mozilla add-ons website.
Browser storage (web storage: cache, cookies, etc.): The modern web browser is a far more sophisticated tool than most people probably realize. In addition to HTTP cookies and web caching, a web server can store data using local and session storage, indexedDB storage, window.name storage and Etag cache storage. If you are concerned about preserving your inherent right to privacy, you have far more to worry about than so-called “cookies” which were once just simple text files.
Crapware: For the purpose of this document, crapware is considered to be code that is included in a browser or browser extension which is not relevant to the functionality users expect from main program. The term crapware encompasses adware, tracking mechanisms and malicious code. Crapware is often added to browser extensions (add-ons) by a marketing company or solo developer for the purpose of monetizing the extension. Crapware can present a significant threat to user privacy and browser security.
CDN: A Content Delivery Network is a service that often hosts reusable content, such as graphics and scripts, which website authors can leverage to make pages load faster.
Domain / Sub-domain / Hostname: For the purposes of this document a domain name and a hostname are interchangeable, both being human-friendly names for a website, such as
example.com. A 1st party domain is the website you are currently viewing, (12bytes.org at the moment) while a 3rd party domain could be a web server which supplies content to the 1st party domain. For example, the web page
http://example.com/video may include a video that is provided by
youtube.com a 3rd party domain. A sub-domain is a separate part of the main domain. For example,
sub.example.com is a sub-domain of
TLD: Top Level Domain. For example,
com is the top level domain in
HTTP/HTTPS: Hypertext Transfer Protocol and Hypertext Transfer Protocol Secure are protocols used for sending and receiving data across the Internet. For HTTP, an unsecured, unencrypted connection to the server is established, while a secure, encrypted connection is used with HTTPS. One reason you should be concerned with unencrypted connections is the fact that it is possible for anyone between your computer and the site you are visiting, including your ISP (Internet Service Provider), to eavesdrop on your traffic and discover exactly where you are going and what you are looking at. While browser extensions like HTTPS Everywhere will attempt to encrypt your connection whenever possible, some web servers simply do not offer HTTPS. For this reason i will again point out the advantage of using a VPN.
UI/GUI: A User Interface, also known as a Graphic User Interface, is the graphical portion of a program usually containing various controls, such as buttons, check-boxes and other widgets which allow you to interact with the underlying code. UI’s are often referred to as “windows”.
Web server: For the purpose of this document, a web server is a computer that is connected to the Internet which hosts (serves) one or more websites.
There are several flavors of Firefox other than the mainstream release, including the Firefox ESR (Extended Support Release) version which is usually an older version that may not contain the latest features, but may be more stable. If you’re running Linux, you may already have Iceweasel installed, which is nearly identical to Mozilla Firefox. Another option is the Firefox Developer Edition which, though i have not tested it with the configuration outlined in this guide, should work fine. Another option is Cyberfox from 8pecxstudios, though, again, i have not tested it with the configuration outlined in this guide. Cyberfox may be more privacy-centric than other versions in that several phone-home features have apparently been gutted, including telemetry, health reporting and possibly the Google “Safe Browsing” feature. One caveat with Cyberfox is that, like Pale Moon, it uses a different format for some of the profile files which requires using a tool to convert your current Firefox profile should you want to import your data. As for the many other custom builds of Firefox, a lot of them are not worthwhile and can/will cause problems due to bugs, add-on incompatibilities, etc.. The last time i tried Pale Moon i ran into some problems as well, though that was long ago and so the issues i had may not be issues any longer so feel free to try it.
Firefox post install cleanup
Some browsers that are based on Firefox may have some extensions, plug-ins and/or search engines preinstalled. Take care to check for this and uninstall or disable any extras that you don’t want. The search engine configuration files are located in the
\Mozilla Firefox\browser\searchplugins folder. I suggest reading my guide, Opting out of the Firefox / Google / Yahoo partnership, for information about how Mozilla monetizes Firefox with the included search engines and what you can do to opt out of this affiliate scheme if you so choose.
If you have already run Firefox, you may notice that it has installed the OpenH264 Video Codec plug-in by Cisco Systems without asking you. Currently this plug-in seems to be used only for the WebRTC feature. If you do not use these features and do not want the browser to load this plug-in, you can delete the
\gmp-gmpopenh264 folder in your profile directory along with the all of its contents. To prevent re-installation, make sure the configuration preferences
media.gmp-gmpopenh264.autoupdate are both set to
false (they already are in the
user.js file linked to below) before the browser is restarted.
The necessary (and not so necessary) add-ons
This guide depends heavily upon the following add-ons:
- uBlock Origin: uBlock Origin, by the same developer of uMatrix, is a powerful content filter which works similarly to uMatrix but is tailored to blocking ads. These two excellent extensions compliment each other nicely when they are configured properly. uBlock can use the same filter lists as Adblock Plus for blocking ads, as well as many more which it cannot. There are currently two versions available; the original by Raymond Hill which has been renamed to uBlock Origin, and a fork by Chris Aljoudi which you do not want to use. uBlock Origin is an active project that offers features not found in Chris’ build, which appears to be dead anyway.
The following add-ons are optional, but recommended:
- Load from Cache: similar to, but not the same as Decentraleyes, Load from Cache forces the browser to reuse cached data instead of downloading it again. The two work well together.
- Clean Links: helps to protect user privacy by striping tracking/garbage parameters from URLs, such as those used by Google Analytics (
- BetterPrivacy: you install this if you are using the Adobe Flash Player plug-in. If you do not want to use the Flash plug-in, and i suggest you don’t (you can still watch videos), you can try the EmbedUpdater add-on which will convert videos embedded in 3rd party websites to use the HTML5 player instead of Flash. Most 1st party sites, such as YouTube, already make use of the HTML5 player.
The following add-ons are completely optional:
- NoScript Security Suite: since uMatrix will be used to block scripts, this functionality is not required from NoScript, though it may add a bit more protection in terms of cross-site request forgeries, click hijacking and possibly other areas. If you use NoScript, i would recommend disabling global script blocking and use uMatrix to handle scripts, though you could do it the other way around if you wanted.
- Cookie Controller: apparently handles cookies, local and session storage, though in a manual and granular way that appears to require significant user interaction. I much prefer to handle browser storage with uMatrix.
For more possibilities regarding add-ons, see my article Firefox Extensions: My Picks.
If you’re running Windows and want to unpack an add-on to have a look at the code, you can use 7-Zip. I believe the built-in Windows archive utility can unpack
.xpi files also, though you may have to change the extension to
Automatic add-on updates
Regarding automatic add-on updates, they are disabled in the
user.js files that are linked to below and i would highly suggest keeping them disabled and checking for updates manually on a regular basis. The problem with automatic add-on updates is that developers may, at any time and without warning, partner with or sell their work to a 3rd party which often results in adding code to monetize the add-on at the cost of your privacy. Examples of some very popular extensions which contain such crapware are Abduction, a screen capture utility, Quick Locale Switcher, a language switcher, FasterFox Lite, a largely useless utility which claims to speed-up Firefox, BlockSite, a content blocker, Google’s Search By Image, a reverse image search utility, and many others. Not all of these extensions contained crapware when they were first developed which is why i strongly suggest keeping automatic add-on updates disabled and reading the change logs and privacy policies carefully each time an update is available. The downside to this is that you need to remember to check for updates manually, perhaps once daily.
For peace of mind, you can also search your
prefs.js file for all instances of “http” and check what the URLs are used for. If you want to disable the functionality you can simply add the preference to your
user.js file and replace the URL with “”, or
localhost, or you could point the URL to
localhost in your HOSTS file.
Browser object caching
Browser caching is a disk intensive activity. If you intend to store cache data, i would suggest storing it in system RAM rather than on your hard drive if you have enough memory available. Even 50 or 100 megabytes of space can help reduce disk workload for websites which you visit repeatedly. In addition to minimizing hard drive wear and tear, your web browser will be able to render revisited pages faster as long the resources for the site are still cached. The settings in the
user.js file below will accomplish this, so if you do not want to store web cache in RAM, you will need to edit the respective settings accordingly. Note that Firefox requires cache size values to be in kilobytes (1024 KB = 1 MB).
Backup your current profile
Before you incorporate the changes we will make, be sure to back-up your current Firefox profile (click here to find it if you don’t already know). The easiest way to do this is to simply to select the profile folder inside the
/Firefox/ folder, press
Ctrl+C to copy it, then
Ctrl+V to paste it in the same place with a different name. I might suggest keeping the original name and just appending
.bak to the copy. Next, delete your current
user.js file if you have one in your profile folder, but keep the one in your backup profile.
The user.js file
We will be changing many Firefox preferences and storing them in a custom
user.js file. You should always use this file to add, remove or change settings that you want to keep across sessions instead of editing the
prefs.js file or using
about:config. If you’re running Windows i would suggest using a quality text/code editor that has syntax highlighting such as Notepad++ or PSPad (the latter being a little simpler to use) for editing code. Linux users will likely already have something suitable installed, like Kate.
You can choose between either my
user.js file, or the Pants/Ghacks file, or create your own if you don’t wish to use either. Both are security and privacy centric, though i am slightly more relaxed with my privacy and security settings in return for a less problematic web surfing experience. My
user.js also contains preferences to enable smooth and dynamic scrolling when using a mouse wheel. My settings are contained in their own section which is appended to the end of the Pants/Ghacks file for the most part. You can find where it begins by searching the file for “
BEGIN 12BYTES.ORG CUSTOMIZATIONS“.
Grab your new
user.js file from atomGit/ghacks-user.js if you want to use my settings, or from ghacksuserjs/ghacks-user.js if you use the Pants/Ghacks version without my settings appended, and save it in your profile folder. Make sure to download the version that corresponds with the version of Firefox you are using, so if your Firefox version is 51.0.1 for example (51 being the major version), make sure you download version v51 of the
user.js file. Pants and i both follow this versioning scheme except i add a revision number after the version, so where his version might be v51, mine will be v51r1 if it is the first revision, v51r2 for the second revision and so on. You always want the latest revision for the version that corresponds to the Firefox version you’re running. If you do not wish to use either one, then you will need to create the file in your Firefox profile directory if it does not already exist. If you already have a
user.js file, you will want to be sure to address any preferences which may be duplicated in your new
user.js file in order to avoid unexpected results.
Editing the user.js file
!!! IMPORTANT !!!
Please read through this section in its entirety before making any changes in order to gain an understanding of exactly what we will be doing and how to revert those changes should it be necessary.
user.js file is updated frequently and i wish to avoid the hassle of editing these settings for public consumption each time i update it, the settings in it are a direct copy of both Pants’ and my personal settings. You should therefore read all of the comments and review each of these settings carefully as it is very likely that you will want to change some of them. See below for my advice on how to edit the existing settings, as well as adding your own.
user.js file you downloaded, you will notice the presence of a bogus preferences, “
ghacks_user.js.parrot“, that Pants and i insert at the beginning of each section of our preferences. Firefox reads the
user.js file from the top down and, if it encounters a syntax error, it will ignore everything following the error. Not good. These bogus preferences are used for troubleshooting and though they are essentially ignored by Firefox, they are very useful to us to help locate in which section the problem lies.
If you want to make changes to your new
user.js file, such as incorporating settings from your old one, or change anything else in it, i highly recommend appending any and all changes you make to the end of the file in your own custom section instead of editing the settings throughout the file you downloaded. You will find an example section has already been created at the end of the file for you to place your personal preferences. There is a very good reason why i suggest placing your preferences at the end of the file: again, this file is updated frequently and therefore it will be a whole lot easier to simply delete the contents of the old
user.js file, with the exception of your personal settings which you appended to the end of it, and copy and paste the contents of the new file above your personal preferences rather than having to sift through the entire file trying to remember and save everything you changed and copy/paste those changes back to the new file. As such, I do not recommend editing any of the settings in the file you download unless there is a valid reason to do so.
Making changes to your
user.js file is easy to do. For example, the value for the preference
browser.tabs.warnOnClose might be ‘
false‘ and you might want to change it to ‘
true‘ to have Firefox warn you when you try to close it with multiple tabs still open. The best way to do this is to copy that line of code (
user_pref("browser.tabs.warnOnClose", felse);) and paste it at the end of the file in your own personal preferences section where you would then change ‘
false‘ to ‘
true‘. Having duplicate preferences in your
user.js file with different values is not a problem since Firefox will use the value of the last one it reads, thus why you need to place your personal settings at the end of the file and not the beginning.
At this point it is important to read all of the comments and review each of the settings in your new
user.js file to be sure each preference is configured the way you want, preferably before you start Firefox. As stated above, any preferences you want to change should be copied to your personal preferences section at the end of the file where you will then make the change to the preference value. Note that if you comment out or delete a setting after having run Firefox, that setting will likely remain active because it will have been copied to the
prefs.js file, so if you want to comment out or remove something from your new
user.js file, you should do so before starting Firefox. If you delete or comment out a setting after you have run Firefox, simply enter
about:config in the Firefox address bar, find the preference, right click it, click ‘Reset’ and restart Firefox. The preference will then be deleted after the browser starts. This only need be done if you remove or comment out a preference and is not necessary when simply changing their values.
Verifying the integrity of user.js
This integrity check should be performed every time you edit or update your
When you run Firefox for the first time after making any changes to your
user.js file, the first thing you should do is check the value of the troubleshooting preference by entering
about:config in the address bar and searching for the
ghacks_user.js.parrot preference. If you are using the Pants/Ghacks config and have not added anything more to the file, then the value should be “
No no he's not dead, he's, he's restin'! Remarkable bird, the Norwegian Blue“. If you are using my
user.js and have not added anything more to the file, then the value should be “
12bytes.org settings loaded” If you have added anything to the file in your personal preferences section at the bottom, and regardless of which
user.js you are using, the value should be whatever you set it to, such as “
user settings loaded“.
If the value for the troubleshooting preference is not what you expect, then you can use it to quickly determine in which section the syntax error lies. It will not tell you on which line the problem exists, but at least you will know in which section to begin looking. Some common mistakes (at least that i have made) are forgetting to end a line with a semi-colon, forgetting a bracket, a quote character or comma, a typo in
user_pref, forgetting to put string values in quotes, or mistakenly putting quotes around integer or boolean values.
Updating the user.js file
When a new version is published, be sure that it corresponds to the version of Firefox you are using as described earlier in the ‘The user.js file‘ section above. If you followed my advice to locate any and all changes to the
user.js file at the end of the file in your own personal section, then your job should be very easy. All you need to do is:
- backup your current profile (might want to dump your old backup if you were happy with the way Firefox was working)
- open your current
user.jsand delete everything above your personal preferences section if you created one
- copy everything from the new file and paste it above your personal preferences section and save the changes
- check the change-log for the new
user.jsfile so you can determine whether you need to change anything in your personal preferences section
- start Firefox and check the value for the troubleshooting preference as described in the ‘Verifying the integrity of user.js‘ section
Between the features offered by Firefox, uMatrix and uBlock Origin, we have some overlapping functionality and it is therefore necessary to configure our settings with this in mind.
After installing uMatrix, click the tool bar icon, then click the black title-bar to access the Dashboard:
Following are my recommended setings for each tab:
The content for the My rules tab will be set using the pop-up UI, so we need not worry about this now.
For the Hosts tab, uncheck all of the options since we will be using uBlock Origin to handle our filter lists.
Next, close the Dashboard tab and click the tool bar icon once again to display the pop-up UI.
In order to deter tracking by the web server, i would recommend configuring uMatrix as shown below. To begin, we need to reconfigure the default global settings — the settings that will affect every website we visit. When configuring uMatrix, it is critical to set the proper scope for the filter settings. In the image below, i happen to be visiting github.com, though the website you are currently viewing does not matter. What does matter is the scope in which we are working. Because “github.com” is displayed in the upper left block, all of the rest of the settings will apply only to github.com:
Since we want to adjust global settings, we need to click the blue block and change the scope to the global scope:
The scope block will change to an asterik:
Other than the scope block, most of the rest of the blocks are divided into an upper and lower half. Clicking the upper half will toggle the whitelisting of a domain or resource, while clicking the lower half will toggle the blacklisting of a domain or resource. What we want to do is globally allow all CSS and images for 1st party domains only and block everything else by default. Click the blocks until your settings match those shown here:
When you are finished, don’t forget to click the padlock icon to save the changes:
The upper part of the pop-up UI should now look like the following:
While the configuration of our global settings for uMatrix is now complete, the result is that many websites will not function properly and therefore we must configure the settings for each site we visit. While this may be a nuisance, the up-side is that we will be better protected against browser tracking, malware and other attacks.
Make sure to read the uMatrix manual to learn how to configure it for each domain you visit. The one very important point i would make is that you note the scope of the matrix before making adjustments to the settings. Remember: if you have the global scope selected (the upper-left box is an asterisk as shown above), then any rules you create will affect all websites, whereas if the scope is set to the current domain being visited, then the rules will affect only that domain.
Because uBlock filters unwanted content, websites will generally load much faster while still retaining all the functionality we require once the rules are configured properly for each site.
uBlock Origin configuration
Once the uBlock icon is on your tool-bar, click it to reveal the pop-up UI, then click the dark colored title-bar at the top to reveal the configuration UI:
Folowing are my recommended settings for uBlock Origin:
Note that we are not enabling the ‘I am an advanced user’ option since all dynamic filtering will be handled by uMatrix.
For the ‘My filters’ tab, i have added a few filters which override any exception filters that may be used in the 3rd party filter lists because i want to be sure they are always blocked:
! override exceptions in existing filter sets - see: https://github.com/chrisaljoudi/uBlock/wiki/Privacy-stuff ||google-analytics.com^$important ||platform.twitter.com/widgets.js$third-party ||gravatar.com^$third-party ||doubleclick.net^$important ||adserver.yahoo.com^$important
The ‘My rules’ tab is empty since we are using uMatrix to create our filtering rules.
The ‘Whitelist’ tab can be left as it is by default.
uBlock Origin usage
We are not using the advanced dynamic blocking features of uBlock Origin since this functionality is being handled by uMatrix. As such, there is basically nothing to configure or adjust after the initial setup, other than possibly disabling uBlock Origin for those websites where you do not want it to run. This is done simply by clicking the big blue power button (this setting will be remembered across browser sessions). Lastly, don’t forget about these important tools:
The eyedropper will open a wizard for hiding page elements that are not covered by the static filters and the other icon will open the network request log which can be extremely helpful for those occasional hard-cases when a website does not display and/or function properly and you have trouble determining why.
You can enable all of the options, though some will be ignored when running when the Event Delegation Mode is enabled. While i prefer to have Clean Links rewrite and highlight links in real time, the developer has stated that the code for accomplishing this is old and unmaintained, therefore i personally use the Event Delegation Mode.
Securing DNS traffic
The Domain Name System (DNS) is an infrastructure which uses DNS resolvers to convert human-friendly domain names (example.com) to IP addresses (255.255.255.255) which are used by the computers that route internet traffic. The problem with DNS is that this traffic is not encrypted or secured and is therefore open to various attacks. To help secure your DNS traffic, please read my guide, Encrypting DNS Traffic (and why you want to).
Testing your configuration
The images below are from the JonDonym IP check website.
The first image is a result of a completely default Firefox release version 39.0 configuration with no add-ons or plug-ins installed.
This next image was captured after the configuring Firefox release version 39.0 as outlined in this guide. While the difference may not seem significant, some key changes have been made to help protect our privacy and security (see the list below the image).
HTTP header test results:
- Cookies: Cookies have been blocked
- Authentication: The sending of authentication data to 3rd party sites has been blocked
- Cache (E-Tags): Although we remain vulnerable to E-tag cache tracking, the threat has been greatly reduced since we are using uMatrix to clear the browser cache at a regular interval. The only way to completely defeat this tracking technique that i am aware of is to completely disable both the disk and memory cache.
- HTTP session: No change
- Referrer: We score poorly here because the IP Check test tool is not aware that we are using uMatrix to spoof the referrer
- Signature: No change
- User-Agent: We score poorly here because the IP Check test tool is not aware that we are using uMatrix to randomize the User-Agent string at regular intervals
- SSL_session_id: n/a (the connection was not encrypted)
- Language: No change
- Content types: No change
- Encoding: No change
- Do-Not-Track: The DNT header has been enabled, though this is largely useless
- plug-ins test: These tests were not run because no browser plug-ins were installed
- Tab name: No change
- Tab history: No change
- Local storage: Local storage is being deleted by uMatrix after it is no longer needed
- Screen: No change
- Screen (usable): No change
- Browser window: No change
- Browser bars: No change
- WebGL: WebGL has been disabled in the user.js configuration file
- Browser type: No change
- System: No change
- Fonts: No change
Following is the uMatrix configuration that was used for the test. All other uMatrix and browser settings are consistent with those suggested earlier:
You can run your own tests using these resources:
- JonDonym IP check (highly recommended)
- See the “Online tests” section of the Firefox hardening guide
General: Both uMatrix and uBlock Origin have the ability to log network requests, similar to how a firewall log might work. This can be a great help when troubleshooting website display or functionality issues. On the uMatrix pop-up UI you will notice a tiny ‘window’ icon that can be clicked to reveal the network request log. See the Logger documentation to learn how to use this feature.
Website does not display correctly: uMatrix: Check that content is allowed for the domain, as well as other domains which supply content to it.
Problems making a purchase: Firefox: make sure to allow 1st party cookies. uMatrix: Check that content is allowed for the domain, as well as other domains which supply content to it. If you are forwarded to a payment gateway such as PayPal during the transaction, make sure that content is allowed for the payment gateway domain, as well as other domains which supply content to it.
Firefox add-ons used in this guide
Further reading on 12bytes.org
- Firefox Extensions: My Picks
- Encrypting DNS Traffic (and why you want to)
- Opting out of the Firefox / Google / Yahoo partnership
- Firefox: Troubleshooting Add-On Issues
- Firefox Scroll Tweak
References and resources
- 2013 Mozilla Foundation Fed 990 Public Disclosure
- About:config entries (mozillaZine)
- Anonymous Surfing with JonDoFox
- Client-Side: WebRTC
- DOM Storage guide (Mozilla Developer Network)
- Evercookie (WordPress plug-in)
- Firefox 39: Tracking Protection for private browsing mode
- Firefox Browser Privacy Notice
- Firefox hardening
- Firefox Health Report
- Firefox user agent string reference (MDN)
- How to block automatic connections that Firefox makes
- How to disconnect “search suggest”?
- How to import Tor Browser profile
- How to stop Firefox from making automatic connections
- How to use RAM disk for cache
- HTML5 Browser Storage: the Past, Present and Future
- Improve online privacy by controlling referrer information
- Increasing anonymity and security of browsers
- IP Check (JonDonym)
- IP Check: Next generation of website tracking analysis (JonDonym)
- IP/DNS Detect
- List of HTTP header fields (Wikipedia)
- Means and Methods of Web Tracking: Its effects on privacy and ways to avoid getting tracked
- Mozilla and Telefónica Partner to Simplify Voice and Video Calls on the Web
- Mozilla Corporation (Wikipedia)
- Mozilla Foundation (Wikipedia)
- Mozilla networking preferences
- Mozilla re-negotiates Google multi-million dollar sugar-daddy deal
- Mozilla Revenue Tops $311 Million From Open-Source Technology (2012)
- Mozilla vs Google on user privacy: WebSockets
- Necko Predictive Network Actions
- Network Information API (MDN)
- OpenH264 Now in Firefox
- Quantifying the effects of Firefox’s Tracking Protection
- SPDY (Wikipedia)
- The Mozilla Manifesto
- ToR Browser Bundle
- Tracking Protection on Firefox
- uBlock Wiki
- Warning: Your Browser Extensions Are Spying On You
Revision historyClick to expand...
- first publishing
- removed all Shim Storage add-on information since this functionality is duplicated in HTTP UserAgent cleaner.
- almost all of the documentation for HTTP UserAgent cleaner was heavily revised.
- various other edits and corrections.
- updated user.js file
- several other small updates and a few corrections
- updated user.js file
- switched uBlock versions since a new fork was created
- updated uBlock images and documentation
- added a “Current notices” section
- misc. other corrections/updates/edits
- updated and added more information for uBlock
- updated one HTTP UserAgent cleaner screen-shot
- misc. other corrections/updates/edits
- updated HTTP UserAgent cleaner information
- for HTTP UserAgent cleaner settings, the suggested settings were split into Suggested global setting for casual browsing and Suggested global setting for best protection.
- updated information for HTTP UserAgent cleaner
- updated user.js file
- minor updates to uBlock information
- misc. other minor changes
- updated some HTTP UserAgent cleaner information
- deleted information for 2 bugs regarding the X-Forward-For setting for HTTP UserAgent cleaner since they were not bugs
- misc. other minor changes
- updated information for HTTP UserAgent cleaner, including adding descriptions for the newly added features, Canvas and Fonts on the HTTP tab
- updated the user.js file
- updated some definitions of terms used in this document
- added some more resources
- updated the information for the Fonts filter on the HTTP tab of HTTP UserAgent cleaner
- updated HTTP UserAgent cleaner information to match changes in version 0.7.4.11a
- added Pure URL as a suggested add-on
- updated contents of the user.js file
- added and edited some information for HTTP UserAgent cleaner
- added more resources in the References section
- updated list of recommended filters for uBlock
- updated user.js file contents
- updated user.js file contents
- updated a few settings recommendations for HTTP UserAgent cleaner
- minor updates to user.js file contents
- added information for securing DNS traffic
- misc. minor updates
- switched to Raymond Hill’s version of uBlock
- updated uBlock filter information
- added Fetch information for new version of HTTP UserAgent cleaner
- updated user.js file contents
- misc. minor updates
- updated uBlock settings to match the current development version (0.9.9.2)
- misc. minor updates
- removed HTTP UserAgent cleaner since it is no longer being developed
- removed Self Destructing Cookies add-on since its functionality can be handled by uMatrix
- added uMatrix
- added more info for uMatrix and IP Config test results
- updated user.js file contents
- various other edits
- Minor edits for uMatrix usage text
- updated user.js file
- removed pcxFirefox as a suggested 3rd party build since i had display corruption issues with it
- updated user.js file contents
- updated user.js file contents
- updated guide information
- updated user.js file and added a revision history to the file
- updated user.js file
- updated user.js file
- minor grammar/spelling corrections
- corrected an error with pref ‘layout.css.devPixelsPerPx’ where the value was an integer instead of a string – this caused all prefs following it to be ignored
- set ‘browser.fixup.hide_user_pass’ back to its default value
- added ‘network.http.redirection-limit’
- added some basic information for configuring the Clean Links add-on
- corrected ‘plugin.scan.*’ values to be strings
- added bogus preferences in the user.js file at the end of each section for troubleshooting potential loading problems
- changed the name of the troubleshooting/bogus preference to
12bytes.org-user-js-settingsand added values to indicate the point at which the file stopped loading – a huge thanks to commenter ‘Pants’ for suggesting the troubleshooting preference and also for suggesting a far better way of implementing it than what i had done (by the way, ‘Pants’ is the author of the
user.jsconfig file used in the ghacks article, A comprehensive list of Firefox privacy and security settings by Martin Brinkmann, so i’m very glad to have his input here)
- removed duplicate preferences in use.js file (see change-log in the file for details)
- removed Extension Defender from the list of recommended add-ons since it’s home page is gone and the code hasn’t been updated in two years
- updated user.js file
- switched to using Pants’ config v0.11 and mostly just appending my settings to the end of his – because this is a major update, no history of changes to individual preferences will be published
- published my user.js on GitHub which was forked from Pants’ code
- removed my user.js code from this page and linked to it on the GitHub page instead
- changed my versioning scheme to match Pants’ where the user.js version coincides with the version of Firefox it was developed for, so v51r1 would equate to version 51.x of Firefox and the r1 signifies the revision, in this case the first revision
- updated user.js to include v51 of Pants’ config – no preference changes so far as i know, just added/removed/changed comments
- updated text in user.js section to account for the new changes
- changes to comments and troubleshooting preference names and values, other minor changes
- updated user.js to version 51r2 – see the GitHub page for the change-log
- updated info here regarding the user custom preferences section of user.js