How do you detect if firefox DevTools is open? [duplicate] - javascript

This question already has answers here:
How to detect if browser console / inspector is *open*?
(3 answers)
Closed 3 years ago.
I've been searching high and low but all I could find are ways to detect chrome Dev Tools and FireBUG Dev Tools. Is there a way to detect, on Firefox, that the Inspect Element/console/Dev Tool is open?

It is impossible to actually hide your client side source code without actually removing said code from being accessed client side. The simple reason for this is the fact that the code has to be downloaded to the client for it to be used. Once downloaded, it's visible to the user. No exceptions. You can do things like 'security through obscurity', but that too is not going to prevent people from downloading/viewing the source. It's just going to make the code harder to read.
If you want to prevent users from seeing your code, you're basically forced to handle the parts of the code you wish to hide server side. This way, only the input and output are visible to users, while hiding the logic that processes it.
There are some other tricks you could potentially do to make it harder to acces your code (not impossible by a long shot), but I wouldn't recommend those either. Those are usually reliant on browser security settings, easily prevented through broswer add-ons, etc.
If instead you want to prevent users from seeing your code, because you're handling security sensitive operations client side, I suggest you go back to web development 101 and check why that's an inherently bad idea.
EDIT: To purely detect if DevTools is open, you can use this: https://github.com/sindresorhus/devtools-detect and simply follow the readme.

Related

Why CasperJS and browsers show different behaviors with CAPTCHA? [duplicate]

Is there any way to consistently detect PhantomJS/CasperJS? I've been dealing with a spat of malicious spambots built with it and have been able to mostly block them based on certain behaviours, but I'm curious if there's a rock-solid way to know if CasperJS is in use, as dealing with constant adaptations gets slightly annoying.
I don't believe in using Captchas. They are a negative user experience and ReCaptcha has never worked to block spam on my MediaWiki installations. As our site has no user registrations (anonymous discussion board), we'd need to have a Captcha entry for every post. We get several thousand legitimate posts a day and a Captcha would see that number divebomb.
I very much share your take on CAPTCHA. I'll list what I have been able to detect so far, for my own detection script, with similar goals. It's only partial, as they are many more headless browsers.
Fairly safe to use exposed window properties to detect/assume those particular headless browser:
window._phantom (or window.callPhantom) //phantomjs
window.__phantomas //PhantomJS-based web perf metrics + monitoring tool
window.Buffer //nodejs
window.emit //couchjs
window.spawn //rhino
The above is gathered from jslint doc and testing with phantom js.
Browser automation drivers (used by BrowserStack or other web capture services for snapshot):
window.webdriver //selenium
window.domAutomation (or window.domAutomationController) //chromium based automation driver
The properties are not always exposed and I am looking into other more robust ways to detect such bots, which I'll probably release as full blown script when done. But that mainly answers your question.
Here is another fairly sound method to detect JS capable headless browsers more broadly:
if (window.outerWidth === 0 && window.outerHeight === 0){ //headless browser }
This should work well because the properties are 0 by default even if a virtual viewport size is set by headless browsers, and by default it can't report a size of a browser window that doesn't exist. In particular, Phantom JS doesn't support outerWith or outerHeight.
ADDENDUM: There is however a Chrome/Blink bug with outer/innerDimensions. Chromium does not report those dimensions when a page loads in a hidden tab, such as when restored from previous session. Safari doesn't seem to have that issue..
Update: Turns out iOS Safari 8+ has a bug with outerWidth & outerHeight at 0, and a Sailfish webview can too. So while it's a signal, it can't be used alone without being mindful of these bugs. Hence, warning: Please don't use this raw snippet unless you really know what you are doing.
PS: If you know of other headless browser properties not listed here, please share in comments.
There is no rock-solid way: PhantomJS, and Selenium, are just software being used to control browser software, instead of a user controlling it.
With PhantomJS 1.x, in particular, I believe there is some JavaScript you can use to crash the browser that exploits a bug in the version of WebKit being used (it is equivalent to Chrome 13, so very few genuine users should be affected). (I remember this being mentioned on the Phantom mailing list a few months back, but I don't know if the exact JS to use was described.) More generally you could use a combination of user-agent matching up with feature detection. E.g. if a browser claims to be "Chrome 23" but does not have a feature that Chrome 23 has (and that Chrome 13 did not have), then get suspicious.
As a user, I hate CAPTCHAs too. But they are quite effective in that they increase the cost for the spammer: he has to write more software or hire humans to read them. (That is why I think easy CAPTCHAs are good enough: the ones that annoy users are those where you have no idea what it says and have to keep pressing reload to get something you recognize.)
One approach (which I believe Google uses) is to show the CAPTCHA conditionally. E.g. users who are logged-in never get shown it. Users who have already done one post this session are not shown it again. Users from IP addresses in a whitelist (which could be built from previous legitimate posts) are not shown them. Or conversely just show them to users from a blacklist of IP ranges.
I know none of those approaches are perfect, sorry.
You could detect phantom on the client-side by checking window.callPhantom property. The minimal script is on the client side is:
var isPhantom = !!window.callPhantom;
Here is a gist with proof of concept that this works.
A spammer could try to delete this property with page.evaluate and then it depends on who is faster. After you tried the detection you do a reload with the post form and a CAPTCHA or not depending on your detection result.
The problem is that you incur a redirect that might annoy your users. This will be necessary with every detection technique on the client. Which can be subverted and changed with onResourceRequested.
Generally, I don't think that this is possible, because you can only detect on the client and send the result to the server. Adding the CAPTCHA combined with the detection step with only one page load does not really add anything as it could be removed just as easily with phantomjs/casperjs. Defense based on user agent also doesn't make sense since it can be easily changed in phantomjs/casperjs.

Close Internet Explorer Programmatically

Is there any way IE can be closed programmatically?
I am trying to build a simple login system for the school I am working at in which a pupil would sign in using a HTML form and when they click the submit button the window will close automatically.
I have tried this using JavaScript (close() seems to be redundant now), VBScript (.Quit) and trying to run a .cmd file to close it externally (Windows Script Host). None of these have worked.
I am not doing this maliciously and I have absolutely no bad intentions of using this code. I understand that it is a universal standard for web browsers not to be closed by client/server side scripts. But, I am, nonetheless, wondering whether this would be possible and how (preferably without installing any other applications).
Is there any way IE can be closed programmatically?
Sure. Find the right IE instance in the SHELL.WINDOWS collection, then QUIT that instance. Or find the right process in Win32_Process, then TERMINATE that process. Or probably dozens of other ways.
None of which will necessarily help, unless you provide a ton more information about what you are actually doing! But that's the consequence of asking "Can I do 'X'?", instead of: "I need to achieve result 'Y', what is the best way to do that?"
You've told us 'X', but not 'Y'.
JavaScript cannot close windows that were not opened via JavaScript.
If websites could close people's browsers, a lot of people would be angry. Your non-malicious intent is unknown to the browser.

Is it possible to prevent JavaScript Worker html5 game manipulation?

In working to make a HTML5 browser game, I can't help but consider the fact that a game like that can't be competitive or valued based on the ease of editing the code of the game through dev console.
For example like this:
https://www.youtube.com/watch?v=lQaTW3vCqC0
The user changes around values of variables and then resumes the scripts causing the game to be directly effected.
I'm thinking of possible ways to avoid such manipulations:
Custom Browser (setup like Tor? custom routing used to detect unhampered browser with no console tools avialable)
detection if dev tools are open Find out whether Chrome console is open , How to detect Chrome Inspect Element is running or not? (but this is only Chrome, what about IE, FF, SF, O?
Any insight or additional thoughts would be great.
Being that JavaScript is a client side language, you'll be hard pressed to provide total security from having it manipulated.

Protect against browser extension injected Javascript code

Browsers allow extensions to inject code, manipulate the DOM, etc.
Over the years, I have noticed lots and various uncaught errors (using window.onerror) on a website (app) I am watching, generated by unknown browser extensions on Firefox, Chrome and Internet Explorer (all versions).
These errors didn't seem to be interrupting anything. Now I want to increase the security of this website, because it will start processing credit cards. I have seen with my own eyes malware/spyware infecting browsers with modified browser extensions (innocent browser extension, modified to report to attackers/script kiddies) working as keyloggers (using trivial onkey* event handlers, or just input.value checks).
Is there a way (meta tag, etc.) to inform a browser to disallow code injection or reading the DOM, standard or non-standard? The webpage is already SSL, yet this doesn't seem to matter (as in give a hint to the browser to activate stricter security for extensions).
.
Possible workarounds (kind of a stretch vs. a simple meta tag) suggested by others or off the top of my head:
Virtual keyboard for entering numbers + non textual inputs (aka img for digits)
remote desktop using Flash (someone suggested HTML5, yet that doesn't solve the browser extension listening on keyboard events; only Flash, Java, etc. can).
Very complex Javascript based protection (removes non white listed event listeners, in-memory input values along with inputs protected with actual asterix characters, etc.) (not feasible, unless it already exists)
Browser extension with the role of an antivirus or which could somehow protect a specific webpage (this is not feasible, maybe not even possible without creating a huge array of problems)
Edit: Google Chrome disables extensions in Incognito Mode, however, there is no standard way to detect or automatically enable Incognito Mode and so a permanent warning must be displayed.
Being able to disable someone's browser extension usually implies taking over the browser. I don't think it's possible. It would be a huge security risk. Your purpose maybe legit, but consider the scenario of webmasters programatically disabling addblockers for users in order to get them to view the advertisments.
In the end it's the user's responsability to make sure they have a clean OS when making online banking transactions. It's not the website's fault that the user is compromised
UPDATE
We should wrap things up.
Something like:
<meta name="disable-extension-feature" content="read-dom" />
or
<script type="text/javascript">
Browser.MakeExtension.MallwareLogger.to.not.read.that.user.types(true);
</script>
doesn't exist and i'm sure there won't be implemented in the near future.
Use any means necessary to best use the current up to date existing technologies and design your app as best as you can security wise. Don't waste your energy trying to cover for users who souldn't be making payments over the internet in the first place
UPDATE (2019-10-16): This isn't a "real" solution - meaning you should not rely on this as a security policy. Truth is, there is no "real" solution because malicious addons can hijack/spoof JavaScript in a way which in not detectable. The technique below was more of an exercise for me to figure out how to prevent simple key logging. You could expand on this technique to make it more difficult for hackers... but Vlad Balmos said it best in his answer below - Don't waste your energy trying to cover for users who souldn't be making payments over the internet in the first place.
You can get around the key logging by using a javascript prompt. I wrote a little test case (which ended up getting a little out of hand). This test case does the following:
Uses a prompt() to ask for the credit card number on focus.
Provides a failsafe when users check "prevent additional dialogs" or if the user is somehow able to type in the CC field
Periodically checks to make sure event handlers haven't been removed or spoofed and rebinds/ warns the user when necessary.
http://jsfiddle.net/ryanwheale/wQTtf/
prompt('Please enter your credit card number');
Tested in IE7+, Chrome, FF 3.6+, Android 2.3.5, iPad 2 (iOS 6.0)
Your question is interesting, and thoughtful (+1'd), however unfortunately the proposed security does not provide real security, thus no browser will ever implement it.
One of the core principle on browser/web/network security is to resist from the desire of implementing a bogus security feature. Web will be less secure with the feature than without!
Hear me out:
Everything execute on the client-side can be manipulated. Browsers are just another HTTP clients that talks to server; server should never ever trust the computation result, or checks done in front-end Javascript. If someone can simply bypass your "security" check code executed in a browser with a extension, they can surely fire the HTTP request directly to your server with curl to do that. At least, in a browser, skilled users can turn to Firebug or Web Inspector and bypass your script, just like what you do when you debug your website.
The <meta> tag stopping extensions from injection does make the website more robust, but not more secure. There are a thousand ways to write robust JavaScript than praying for not having an evil extension. Hide your global functions/objects being one of them, and perform environment sanity check being another. GMail checks for Firebug, for example. Many websites detects Ad block.
The <meta> tag does make sense in terms of privacy (again, not security). There should be a way to tell the browser that the information currently present in the DOM is sensitive (e.g. my bank balance) and should not be exposed to third parties. Yet, if an user uses OS from vender A, browser from vender B, extension from vender C without reading through it's source code to know exactly what they do, the user have already stated his trust to these venders. Your website will not be at fault here. Users who really cares about privacy will turn to their trusted OS and browser, and use another profile or private mode of the browser to check their sensitive information.
Conclusion: If you do all the input checks on sever-side (again), your website is secure enough that no <meta> tag can make it more secure. Well done!
I saw something similar being done many times, although the protection was directed in the other way: quite a few sites, when they offer sensitive information in a form of text would use a Flash widget to display the text (for example, e-mail addresses, which would be otherwise found by bots and spammed).
Flash applet may be configured to reject any code that comes from the HTML page, actually, unless you specifically expect this to be possible, it will not work out of the box. Flash also doesn't re-dispatch events to the browser, so if the keylogger works on the browser level, it won't be able to log the keys pressed. Certainly, Flash has its own disadvantages, but given all other options this seems the most feasible one. So, you don't need remote desktop via Flash, simple embedded applet will be just as good. Also, Flash alone can't be used to make a fully-functional remote desktop client, you'd be looking into NaCl or JavaFX, which would make this only usable by corporate users and only eventually by private users.
Other things to consider: write your own extension. Making Firefox extension is really easy + you could reuse a lot of your JavaScript code since it can also use JavaScript. I never wrote a Google Chrome or MSIE extension, but I would imagine it's not much more difficult. But you don't need to turn it into an antivirus extension. With the tools available, you could make it so no other extension can eavesdrop on what's going on inside your own extension. I'm not sure how friendly your audience will greet that, but if you are targeting corporate sector, then that audience is, in a way, a very good one, as they don't get to choose their tools... so you can just obligate them to use the extension.
Any more ideas? - well, this one is very straight-forward and efficient: have users open a pop-up window / separate tab and disable JavaScript in it :) I mean, you could decline to accept a credit card info if the JavaScript is enabled in the browser - obviously, it is very easy to check. This would require some mental effort from the users to find the setting, where they can disable it + they will be raging over a pop-up window... but almost certainly this will disable all code injection :)
This wont work, but i'll try something around document.createElement = function(){};
That should affect client side scripts (greasemonkey)
You can also try to submit the current DOM using an hidden input
myform.onsubmit=function(){myform.hiddeninput.value=document.body.innerHTML;} and check server side for unwanted DOM elements. I guess using a server side generated id/token on every element can help here (as injected DOM node will surely miss it)
=> page should look like
<html uniqueid="121234"> <body uniqueid="121234"><form uniqueid="121234"> ...
So finding un-tracked elements in the POST action should be easy (using xpath for example)
<?php
simplexml_load_string($_POST['currentdom'])->xpath("*:not(#uniqueid)") //style
Something around that for the DOM injection issue.
As for the keylogging part, i don't think you can do anything to prevent keylogger from a client side perspective (except using virtual keyboard & so), as there is no way to discern them from the browser internals. If you are paranoid, you should try a 100% canvas generated design (mimicking HTML element & interaction) as this might protect you (no DOM element to be bound to), but that would mean creating a browser in a browser.
And just that we all know we cannot explicitly block the extensions from our code,
one another way can be to find the list of event listeners attached to key fields like password, ssn and also events on body like keypress, keyup, keydown and verify whether the listener belongs to your code, if not just throw a flash message to disable addons.
And you can attach mutation events to your page and see if there are some new nodes being created / generated by a third party apart from your code.
ok its obvious that you will get into performance issues, but thats a trade off for your security.
any takers ?

is there a way to disable javascript debugging on a live server

Is there a way to tell debugging tools (firebug and the likes) never to be enabled for your website regardless of user's browser configurations?
no.
client is free to do whatever it sees fit with your javascript. You may try to obfuscate - but this is not effective against determined developers
Scripts, HTML, CSS, Images everything is loaded to the client before the page opens. So he can do anything he likes with what he has in his system. There is no way to disable it.
Even If there is a possibility of doing such, he can remove that as well.
So, basically its a wasted effort.

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