Hi, and welcome back to section three net Cat Penetration Test.
In this video, we're going to talk about packet sniffing and net cat.
You have a better understand about all the information received about the
methods of enumeration, like scanning and Benny grabbing.
It's important to go deeper and examine the packet level.
There are numerous services for all operating system that do not exchange
as key text banner. Instead,
the communication is in binary digit,
and the response has to be in the same format for this kind of operating.
The use of a packet sniffer will help to decoding this type of messenger.
So here in my cardio Linux environment, let's do a test and check the,
the packet formation. For our test,
we communicate in a net views services that is listened for
incoming connection on T C P port 1 3 9.
Almost a connections made.
The server will wait for a binary command for a client and react accordingly.
Net views is the account for network basic input output system,
and is a basic protocol used for transmitting data between two computers
on the same network segment.
It was used as the four windows file sharing and printer sharing.
So in my network here, I have a Windows mean net views started and open it.
So let's start our test. First of all,
I open at polyol
and I'll connect me this, uh,
service or I use netcat
and this is the, the IP of my, my windows
that is using and open our net use, uh, connection.
So first let me use, uh,
thefor mode and this level I don't have any details because I don't use the the
dash V. Okay, let me use
dash V to get more information. Dash
bv. Okay, so now I have more details about the connection.
So this is the ip, the host, this is the the port,
and this is the service nets. S s n,
the n b uh, SS, s n,
that that's mean net BES session service. And the connection is open.
And now I will insert a messenger here,
but I want to verify the kind of response. It's so long.
So zero packet was sent and zero packet was received.
It let me, uh,
execute again and put a messenger.
So look, I was able to send a messenger. Okay,
parting the number of characters. I received a response here.
This is the confirmation, but was not comprehensive to us.
Okay? So, uh, the meaning of using, for example,
another tool,
APEC filter APEC in this needer to get this messenger
and, uh, work about the, the format about,
about the decoding of the, of messenger. This messenger, okay.
An option here is to use,
I use a tool that you use is a binary, is a XMO tool. Uh,
able to, to get more details about this. This me, for example,
I'll put a command here and check the result. For example,
I use Echo messenger, uh,
a command with the messenger. When, when you text messenger,
I'll use a pipe to use this command.
In the left will be, uh, input for the command in the right,
so will be my net cat command.
Okay? So the, the messenger, hello,
there will be input for the connection that we made for
this host and this ip. And the result of all this,
I will put another pipe that will be, uh,
input for another comment will be X X D X X DEXA XMO
text mode display.
So I will able to see the ax mode of the input and input
will be the result of the connection made with this hosting n i
p. Okay. So that's it.
Now look the difference of details of the response here,
we have no, no visible, uh, result here. We,
we have more information, okay? But we know, uh,
messenger send or receive it here we have, we,
we send our messenger here and we receive it, but was not comprehensive to us.
Now in this comment here,
I receive the message was to receive it and, uh,
we coordin for this, this common here X X D, this tool. We are all, uh,
available to, we're able to get the messenger.
So this message is like this, uh, this is the, the, the characters,
okay? And to have more comprehension about this,
we are use a packet sniffer,
in this case white shark to get a more dictal, uh, in a high level.
Okay? And that white shark is able to get this, this, this packet.
We will see the packet that was, was a request and a response. Okay?
And we see a more details about this information.
So let me start wire shark, I'll start wire shark.
Listen for our communication here like this.
And I'll do again the messenger, the, the comment.
Okay,
let me stop here and let me verify that's here.
This was the protocol. N B S S, that's being net build session service.
And this is my messenger. Hello there. Okay,
this is all the layers. D, C P ip, okay?
And this is the protocol with the machine. Have there,
and, and this is our response from the server.
So we have the layers here, D, C, P and the, the,
the layer, the, the package as s n like this.
And this was the package here, okay? Is the same here,
like this. So this is all the, in this case was, uh,
a messenger error. Okay?
Eight F because the,
the net views is rating for specific protocol, uh, is a, a specific, uh,
messenger common. So we send a regular string,
but we have all the, the procedures to send and to communicate.
But the response was, uh, error.
But using a package sniffer,
like while shark was able to get,
first of all to see the communication here
and to see again, uh, all the,
the format of this protocol, okay?
Was example for this, uh, three byte. Here was a length here.
Uh, N H P is AI specific error messenger code, a whole code.
So the point here is using a packet sniffer and using ACA two,
we have more details about all the information,
all the package that we are trying to, to get here.
And this is very interesting because this give us to us more information,
uh, and adding our scanning or uh, be grabbing.
In this video we saw an an introduction about packet sniffing and netcat.
The next session, we'll take a look about transferring data with Netcat.
I hope to see you there.