Creating a Desktop App Blocker Simple Guide in Juliar

October 12, 2016 | Views: 1597

Begin Learning Cyber Security for FREE Now!

FREE REGISTRATIONAlready a Member Login Here

Hey guys,

Today we will be building a simple Desktop App Blocker. This will work on any operating system: Windows, Mac, Linux/Unix.  It is not necessary to use a specific operating system. That is a beauty of Juliar.  It is the same Juliar script  which will work on any operating system. An Android version of Juliar is coming soon so you will be able to launch Juliar scripts on your phone.

This guide can be used for both System Administrators who want to prevent users from running certain apps, and for an Ethical Hacker who wants to block access to a certain App.

Firstly, grab latest Juliar version at https://www.juliar.org/downloads.ju

and download the version that pertains to you.

Then double click on Juliar(Juliar.exe) and you should see something like “Welcome to Juliar”

We will be using the following *Juliar * command

  • *getprocess*    –gets process using name and outputs it’s ID/IDs
  • *killprocess * –kills process by ID/IDs
  • *loop=Infinity * — loops something infinitely
  • *wait * — waits in seconds (default  3 seconds)

For this example, we are going to  use “firefox”. Because we don’t want people opening firefox for some reason. So we will first need “firefox” ID/IDs ( I am saying IDs because some applications like “chrome” open up many processes and hence have many IDs). Let’s open up firefox before we do anything. Let’s type *getprocess firefox * in Juliar and press enter and we will get some number….OK that’s our processID. Next let’s try to kill it with Juliar by typing:

*killprocess *getprocess firefox **

This will kill all firefox processes, so you should see firefox shutdown.

No problem. Simply open firefox again! That’s where *loop=Infinity * comes in.  This will continually try to kill process.

So if we have all that, why do we need *wait * ? Well, Juliar will try to execute the infinite loop as fast as possible. This will make the processor work very hard and we don’t want that. That’s where *wait * comes in. Wait safely “pauses” the program for some time period without tying up a processor. So in an infinite loop is strongly recommended to execute wait. We will wait for 1 second. Although, *wait * allows up to 0.001 seconds, we will use 1 seconds for simplicity.  So our final program now looks like:

*loop=Infinity             *killprocess *getprocess firefox**                *wait 1*    *

That’s it! That’s your whole program in Juliar…

Let’s run it! Test it by trying to open up Firefox…Aaah. We cannot! It just automatically shuts down 🙂

We just fox blocked ourselves!

You may get an ERROR such as ERROR cannot kill the process ID. That means, Juliar gets all IDs of firefox for example via *getprocess firefox * and then tries to kill all the processes. However, some processes are dependent on another, so if one gets killed another one can get killed. When Juliar, displays such an error, usually it means that Juliar has already killed a process that caused another process to be killed. You can safely ignore such errors 🙂

Get your magnifying glasses on Ninjas and Enjoy! Try inserting other programs and play around.

I’ve noticed that *Juliar * is becoming more popular. The Facebook is growing and I am getting Twitter mentions. However, I do not receive much feedback other than that. If you have any suggestions or comments please let me know at https://www.juliar.org/forums

Share with Friends
FacebookTwitterGoogle+LinkedInEmail
Use Cybytes and
Tip the Author!
Join
Share with Friends
FacebookTwitterGoogle+LinkedInEmail
Ready to share your knowledge and expertise?
Comment on This

You must be logged in to post a comment.

Our Revolution

We believe Cyber Security training should be free, for everyone, FOREVER. Everyone, everywhere, deserves the OPPORTUNITY to learn, begin and grow a career in this fascinating field. Therefore, Cybrary is a free community where people, companies and training come together to give everyone the ability to collaborate in an open source way that is revolutionizing the cyber security educational experience.

Cybrary On The Go

Get the Cybrary app for Android for online and offline viewing of our lessons.

Get it on Google Play
 

Support Cybrary

Donate Here to Get This Month's Donor Badge

 
Skip to toolbar

We recommend always using caution when following any link

Are you sure you want to continue?

Continue
Cancel