In simple terms nuts cut is a computer utility for reading from and writing to network connections using
TGP or UDP.
When we see a reading from and writing to a network it means that the utility runs in two modes client
board and the server mode.
Netscape is a small tool but actually it's a very powerful one especially used in forensics.
As you can redirect the file output of the local machine to the forensics workstation you are working
on.
We use that car to scan and connect to an arbitrary port to create the listener on a local court to
transfer files and for remote administration and we will see examples to help to bind the shell and
how to bind a reverse shell.
The syntax for using that card is NC then the flag options then the target IP address then the port
and the parameters are added for listen mode.
E in order to execute the program after the connection is established and that would tell the program
not to perform DNS lookups V for verbose which shows us some status of the connection of any errors.
The connection is established etc. So the console.
We will be able to see some information and B for the local port let's cut usually comes installed on
county Linux but it is not installed by default on Windows machines so you can go to any of these links
and download the compiled version of windows and start using it in our three examples or for examples
we will use.
This is structure here to Kelly that we are using is a local version which has a private IP address
applies before a public IP address or before a firewall or rather at this case and we will connect remotely
to a Windows machine that is hosted on the cloud.
Having a public IP address one does machine can as well be the Windows machine that we downloaded earlier
on VM where but for the sake of giving a real example we will use this scenario in the first scenario.
We will connect to ports on a remote machine so we will scan the port and see if this port is open and
connect to the port.
What we will do is to open a terminal on our Kelly machine and write the command and see for that cat
then barometers and the for verbose.
Then we will put the IP address of the cloud when this machine which is 1 7 3 2 2 4 a dot 1 3 2 dot
230.
I know that one of the ports on this machine which is 8 2 1 0 is open so let's see this is the output
of NC.
It tells us that it connected to this IP address on port 80 10 and this port is open.
So this tells us lots of things.
First of all it tells us that we were able to manage to have a conversation with this cloud server and
it tells us that port 8 0 1 0 is open.
The next example we will bind a port and listen to incoming connections.
So here we will go to the Windows Server.
This this is actually the Nets cat files that I have downloaded from the Internet.
These are compiled for windows so we just put them in the folder and navigate to the folder on the desktop.
Here you issue the command of N C minus n l the B and then lets select the port of 2 2 2 2.
So what are we actually doing here.
So we are issuing the command of nat cat and we are passing the parameters of and as we said don't perform
DNS look up and or listening.
What's happening here is that nat cat is listening to the port.
Two two two two and a verbal is more which is show me any information about the connection.
So we just hit enter okay.
And now we see that it is listening to any connection that is coming to port to to.
So now we go to our machine candy machine and from here we will connect remotely to the cloud server
or cloud window machine and try to open a conversation with the server so we'll issue the command and
C minus and V then the IP address 1 7 3 2 4 8 2 8 1 3 2 add up to a 30 and then we'll specify the port
and press enter.
So to tell me that this sport is now open.
So actually now there is a tunnel between these two computers the county which is private on the private
network.
And the server the Windows Server which is which is on the Internet.
So what can we do now.
Actually we can open a chat session for example.
So let's say hello from Cali and the press enter our finger to the Windows machine.
You'll see this message popped up here and from the windows machine I can as well reply hello from Windows
machine.
If I go to the Cally I'll see that the message has been popped up here as well.
This is a simple demonstration and I think it's not that useful I mean to chat between two server but
that actually demonstrates that lots of capabilities of the net cut utility.
The third example will show is to set up a listener and redirect any incoming input to a file.
So actually we were transferring files from one computer so another for this purpose.
I'll go to my windows machine if I need to exit this press control see and from this terminal here I
will issue the command of N C minus an arrow v B then on the port and then I say that anything coming
on this port please redirected to this file.
Call it like up on that x.
So now it's listening and whatever comes on this point to be redirected to open the XY on our candy
machine we will transfer it file so let's locate any file for this purpose.
I'll try a locate as BD I'll select this file here.
The E X E.
Sounds like this SBT got its e.
I'll copy it I'll copy it and then I will issue that kind of N C minus envy the IP address
then we will connect on the port.
2 2 2.
Then we will put the SBT by issuing this command we have transferred the SBT file the Beatles the XY
file from the copy machine to the Windows machine.
If I go here I will see that a new status has been issued connection from this IP address by public
IP address of my router.
So if I quit this session and go to DIY R to this to listen to their activity I will be able here to
see this file output that exceed that I have transferred from my Kelly machine to my windows machine.
If I open this here I'll be able to see this file and this is the size and the creation date and time.
So the fourth example is about the remote administration as we saw earlier and this presentation here
the slide we have the two machines the Kelly which is on our LAN and the windows machine which is on
the clock.
Suppose that the user using the cloud machine wants a remote assistance from the user using candy machines.
So the user using Kelly will look on remote key to the user on Windows machine.
They use it on the windows machine will issue this comment and see minus and the B then they put 2 2
2 2 then minus E C and D E C this command says any user who connects three more key on the port.
2 2 2 2 will be redirected to the command prompt the command or the console the command of the exe from
the Kelly site we will issue this command and C minus and V then the IP address
then deport when you press enter you will be dedicated to the command line of Windows.
So now you have full control to remotely manage windows through the command line.
It can this defines here and Sky's the limit.
Now we have full access and full control over the command line and the last example suppose that the
user using Carly wants a remote assistance from the use it on the windows machine but they use it on
Kelly is behind a firewall and his IP is not tied so he cannot expose these services point as the windows
guy did previously.
So in this case we will go to the windows machine here.
Let's stop this and we will issue this command and C minus and LGB and then this point then from our
candy machine we will put this command and C minus and the IP address
then the port where want to connect to then parameter minus E which is to run a program and which program
we will run.
Surprisingly it's the best woman.
So the connection is now open.
If you go to our Windows machine and run it command a Unix command like I f config and press enter.
Now we have full remote access to the bash terminal on Cally and you can see here that the IP address
is 1 and 2 that 1 6 8 to 1 on that 130 and all the other information you can as well issue any other
come on.
So as you guess you can use Netscape as a backdoor to access systems one of the drawbacks of net cash
is that the traffic is not encrypted.
For that we have an enhanced version of net cat called and cat.
It is important to note that because running that cat creates open ports on your machine the use of
not cat can present a significant security risk if she use it improperly so make sure not to leave that
cats running while you're not using it.