Thursday, 7 July 2016

Safe Browsing: Avoid running unnecessary JavaScript



Safe Browsing: Avoid running unnecessary JavaScript
It’s not against JavaScript, but against its misuse…!
[1]

I just saw a post linking to a popular news website, in the feeds of Facebook, I clicked on it and got redirected to their website. It took a long time to get loaded, because it was the first time I visited that site. Later a warning message was shown that asked me to disable the add blocker, in-order to continue for reading the article in that website…![image 1]

image 1


image 2
After experiencing this I just decided to look at the scripts that were blocked, a small research on all those domains reviled that most of them were used for advertizing. [image 2]


So the website wants to earn free money from our clicks, the publisher of adds throws some random add in the form of image, text or video, and demands a visitor to download it. If questioned (by blocking), then the website won’t respond at all. Isn’t it a digital ransom …?


Well generation of revenue by showing some adds is not bad, but exploiting visitors for this is messy…!



We all know the importance of JavaScript in today’s websites; they are used to create attractive GUI, visual effects and the most striking feature is AJAX, unfortunately this is the most exploited feature…! 

One can write JavaScript codes to capture touch, mouse and keyboard events, this blog has got a small live audience tracker, that can identify the geo-location, operating system platform of the visitor, but the advanced pro trackers can capture even more data of yours. Don't worry I have no such mechanism in here..

But in the worst case the key strokes and can be sent to server in the background. The best part is, all JavaScript codes will be downloaded in the client end and a client can see the source code, but how many of us see those source codes…? What if the source is encrypted…? Hi don’t worry, I’m not trying to scare you, but this is possible.


image 3
Coming back, the  website suggested to disable the add-blocker [image 3], in-order to allow their add scripts, but I just disabled the JavaScript in my web browser for some time, to override this restriction and got access to the website content. 

    But disabling the JavaScript in the browser will make you lose the whole website experience, created by the developers and most of the websites becomes unusable if the JavaScript is completely blocked. But enabling the scripts blindly may lead to privacy issues. 


What I found was a simple browser plug-in will help effectively in encountering this issue. A right plug-in that can monitor unnecessary script on the web page and prevents it from downloading, it not just saves your bandwidth but also reduces the page load time. More over right information will be prevented from reaching the wrong hand...!



References:
[1] http://www.omgchrome.com/chrome-software-removal-tool-beta/
https://www.fsf.org/blogs/community/gmail-jstrap

http://www.gnu.org/philosophy/javascript-trap.html

Tuesday, 28 June 2016

Resume an Interrupted Download



In this article I will tell you how to resume or continue an interrupted download.

      If the download link is static then we may not face the problem, but a dynamic download link having expiry time, this will cause a big problem specially while downloading huge files…, 

"I was facing such troubles while downloading movies from Youtube. But now this problem is been handled…!"

To know more about dynamic download link or auto expiry links, please refer the post here.

Before proceeding further, I believe you got to know about dynamic download links. Instead of using your web-browser for downloading purpose, it is always a best practice to have a download manager. Like a torrent client, have separate download software. In this case, I recommend Internet Download Manager (IDM) or Free Download Manager (FDM). IDM has got page crawlers, so if a media file exists on a webpage, then you may see a download button next to it…! So it makes very easy to download, but sometimes its bit annoying...!

The trick I’m sharing here is been successfully tested with IDM v6.25

A.    Normal Download:

                i.            Obtaining the URL of media File:
In-case of a video file its better to use http://catchvideo.net/ it’s completely free, no to run applets and the best  part is it gives you variety of formats to download..! The image linked here will tell you how to obtain the download URL manually.




     ii.          Feed the URL to IDM:
Open the IDM and click Add URL button, if you have copied the URL, then IDM will read data directly from the clipboard, click ok, within few seconds the new window will show the size of file, only then continue your download.

         B.     Continue the interrupted download:
 
I believe you have read about the dynamic download links, so I’ll straight away continue with the trick to resume.

i.                    Follow the step-i, in section A, to                                   obtain the new download link.

ii.                  Open IDM, go to properties section of interrupted download. Now replace the old URL in address space (highlighted in blue), with the new URL you just         obtained in step1. Now resume the download…!