Practice English Speaking&Listening with: Learn Kali Linux Episode #23: Macchanger (Part 2)

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Hello everybody and welcome to this tutorial. Today, I will talk about how you

can actually schedule tasks to run at reboots, or how you can schedule tasks to

run at a certain point of time. Namely, this connects to the previous tutorial

as this is a follow up, how you can set a script or a command to

change the MAC addresses of your interfaces at startup. So every time you

basically reset your computer, or something like that, every time you turn

off your computer and turn it back on, not only does it give you a random

address that anonymizes you further on wireless networks, but rather instead you

are effectively making sure that you will absolutely never use your own real

MAC address anywhere. That's not a bad idea. You might think to yourself,

oh, well, I can just why would I need to do that I can just change it every

time I need to change it. Well, you forget, trust me. You don't think about it all

the time, and it can be painstaking to think about it all the time, not a good

idea, and you will find yourselves in a situation where you

will forget to do it and you will need to do it. That can cause a bit of

inconvenience, not a good idea. It's far simpler to set a cronjob

once, and it's gonna run every time you reboot your computer, change your MAC

address, and that will be just perfect in such a way you will effectively insure

that you will absolutely never on any Wi-Fi network use your own MAC address.

Or on any network, of any kind or sort. Now if we take a look in ifconfig,

I don't actually have any wireless interfaces configured here.

Primarily, because this is a virtual machine. We will be doing some of the

things on my other machine, on Fedora which is my host machine, but for the

time being we will use eth0, my wired interface, as an example. But you can just

as easily do this with any other interface that you have. All

that is really different is the name of interface. So, for example, this one is eth0,

wireless1 would be eth1. On my fedora Fedora OS it's vlp2s0,

that's the name of a wireless interface. Why they have named it so I have no idea,

but so it is. In any case, what you would need to do is let's just go ahead and

clear the screen first. There is something called cronjobs, so cronjob

in pretty much every Linux distribution out there, this is what you use in order

to schedule tasks to run for you in an automated fashion. So what you need to

type in is crontab - - help, press Enter, and there we go. We have a help

menu. It's really small, there aren't that many options, the tool is fairly simple.

You use - e to edit user's crontab, you use - u to specify the user

for which you wish to edit the crontab. That's not a bad idea either

if you have lots of users on the system, or something of a kind, but other than

that by default it will edit the cronjobs of a a current user. So, you can just

type in, before we start typing it in you can also list the user's crontabs,

delete the user's crontabs, very important, and you can also

always use - i to prompt before deleting. Primarily, because when you

delete something in Linux it's not like in Windows. Once you delete it's gone,

and it's gone. There are some methods of retrieving that sort of information,

but more likely than not it's permanently gone. You will find it very

difficult to retrieve information that you have deleted through the usage of

terminal. For example, using the RM command, or something of a kind, yeah.

I've talked about this previously, but I just wanted to remind

you because it is very important, and it has happened to me lots of times that I

deleted something which I either could not retrieve, or I could only retrieve

it but it was fragmented and there were only bits and pieces of it.

So not a good idea. Anyway, enough about that. Let's

go ahead and start editing our scripts that will run on startup. So just

type in crontab - e, press ENTER, and there we go.

We are prompted with this file. This is opened with vi editor, so we will need to

go through some of the basics. There it says edit this file to introduce tasks

to run by cron. I strongly advise reading through this entire file. It's very small.

Like look it goes from here to here so that's the entire readme file.

Just read it. I'm 99% sure that you will be able to

understand pretty much everything that is written here, I will explain some of

the things, but if you find anything unclear that you see here, feel free to

post it in the questions section. Over here the last line is actually the

format. So you got minutes, you got day of the month, you got day of the

week, you got a command for the meaning of each of these separate sections. You

can read this file here. So mon is month, the dom is day of the month, this is hour,

this is minute, and so on, and so forth. So just go through this file, read

through it, and you will understand this format to the fullest extent. But, for the

time being, here is the command that I wish to use. In order for you to

edit pretty much anything in VI, VI is a linux text editor,

you need to open a file and then press I. Just go ahead and press I on

your keyboard, letter I, and it says you are currently in the insert mode. You can

see how I'm highlighting it, now it says insert, and now you can

actually type things in. What we want to type in is @reboot, and then

type in the command macchanger - r,

eth0. That is the command that we use in order to randomize the MAC

address of our eth0 network interface. And here you have at reboot. So when do

we want this to happen? At reboot we want it to happen. When we reboot our machine

execute this command. If you wanted to run a script, or something like that, you

would just need to specify a path to that script and then a command to

execute it. But for the time being, we're not gonna use that. We're just gonna use

a command in order to randomize the MAC address of our network interface. So just

press escape now to exit insert mode, and press : on your keyboard. So just press

colon on your keyboard and you will be prompted with a command line here. In the

command line you need to type in w for write, so write these changes to a file,

and then in addition to W you also need to write q, quit. After you've

written to a file I want you to quit the file. If this doesn't work you

can also add an additional argument which is an exclamation mark to forcibly

do it, but there is no need in this example, it's gonna work. So

quit, there we go. This says installing new crontab, excellent! So we'll just go ahead

and clear the screen, type in ifconfig eth0, wait, no, I don't want to use

that one. I'll do mac changer - s to show me the MAC address

of my interface, eth0, press Enter, and you see it says permanent Mac, this

one. Current Mac that we are using, same one, pretty much. I don't know this is the

manufacturer Cadmus computer systems, whatever. Just go ahead and reboot the

computer, and after the reboot we will see a different MAC address there. Now

you don't need to remember the whole MAC address to verify this, just remember the

first pair, the first two digits, the first two

places, actually, not digits, it was 08. 08 were the first two places that were

occupied in the MAC address. Once we reboot the system I will start up the

ifconfig...actually not the ifconfig. I will use macchanger from now on to actually

verify the MAC addresses of my interfaces. Even though, even though, that

is not a good thing. You should really be using ifconfig, primarily because it is the

universal way of checking a MAC address on pretty much any Linux distro

out there. While on the other hand, Mac changer is most likely only installed by

default on Kali Linux, and pretty much any other distro does not have it installed

by default. So just go ahead and use ifconfig. No, I do not wish to login

this test, I wish to login as root. So, root, test, there we go.

We're being logged in at the moment. Sorry for any delays, this is a virtual

machine so it's bound to have some slight delays, but surprisingly I have

found it very efficient. It's working at a relatively fast pace. I'll just go

ahead and open up our terminal, type in ifconfig, and you can see that the

hardware address has been changed indeed. This one is no longer 08. So to confirm

this further, we'll just go ahead and type in macchanger -s eth0, excellent! So

you see permanent Mac is this, current Mac is this. It's of an unknown type,

unknown manufacturer that is. You can take a look at the macchanger help

menu to specify the type of a MAC address that you want it to assign to

your interface. You can play around with that. I strongly advise that you do. Again,

if you have any questions in regards to that, feel free to post them, I will be

more than happy to help you out in any way that I can. In any case, I bid you

farewell, and I hope to see you in the next tutorial.

The Description of Learn Kali Linux Episode #23: Macchanger (Part 2)