Instructor: Now that we know how ARP spoofing works. 2 2
Let's see how we can run this attack 3 3
and redirect the flow of data 4 4
so it flows through our device. 5 5
This will allows us to intercept data 6 6
and see everything sent to and from a target computer 7 7
including, usernames, passwords and so on. 8 8
Now there are a number of tools that can be used 9 9
to run an ARP spoofing attack, 10 10
you can even build your own tool 11 11
and I covered this in my Python programing course. 12 12
But in this lecture I wanna show you 13 13
how to use a very simple yet reliable tool called arpspoof, 14 14
then in the next lectures we'll use 15 15
a tool called BetterCAP because it has more features. 16 16
Basically, the main reason why I want to cover arpspoof 17 17
in this lecture, because it is a very simple tool 18 18
but it's very reliable. 19 19
It's also ported to many operating systems, 20 20
including iOS and Android. 21 21
Therefore if you learn how to use it here 22 22
you'll be able to use this tool 23 23
on all of the other operating systems. 24 24
So you can only use this tool to redirect the flow of data 25 25
and make it flow through your computer, 26 26
and then you'll have to use another tool 27 27
like a packet sniffer like Wireshark to analyze this data 28 28
and do more stuff with it, 29 29
and we'll cover all of this later on in the course. 30 30
Now, using arpspoof is very simple. 31 31
First, we're gonna have to type its name. 32 32
So it's arpspoof then we're gonna do dash I, 33 33
to specify the interface that is connected 34 34
to the target network and in my case it is eth0, 35 35
because that's the interface that's connected 36 36
to the network. 37 37
So if I do, ifconfig, 38 38
you'll see eth0 is the interface that's connected. 39 39
Now as you can see I'm gonna be running this attack 40 40
against my virtual not network. 41 41
You can run this attack against any type of network, 42 42
even Wi-Fi networks and I will cover that 43 43
later on in the course. 44 44
But for now just until you properly understand 45 45
how this works, I highly recommend you 46 46
do like I'm doing right now 47 47
and test the attack against the virtual node network. 48 48
So all you'll have to do is make sure the Kali machine 49 49
and the target windows machine are both configured 50 50
to use the same node network. 51 51
So, we're gonna do dash t to specify the target 52 52
and my target is at 10.0.2.7. 53 53
As you can see in here that is the IP of my target. 54 54
And I'm gonna have to give it the IP of the gateway 55 55
which is 10.0.2.1 56 56
as you can see in here. 57 57
Now this will spoof the target, 58 58
telling him that I am the router. 59 59
We'll also need to run this command once more in here. 60 60
So, I'm gonna clear the screen and again I'm gonna do 61 61
arpspoof -i eth0 62 62
and the target this time is going to be 10.0.2.1 63 63
and 10.0.2.7. 64 64
So right now we're gonna be telling the router 65 65
that I am the victim, 66 66
so the first one will fool the victim, 67 67
the second will fool the router. 68 68
Now keep in mind this attack will work against both internet 69 69
and Wi-Fi or wireless networks. 70 70
I'm running it right now against the virtual networks 71 71
which acts as an internet or a wired network, 72 72
but the attack can be executed exactly the same 73 73
against wireless networks. 74 74
All you have to do is connect a wireless adapter 75 75
to the Kali machine, 76 76
connect the adapter to the target network and use it. 77 77
So the same concept as the networks kinda applies. 78 78
You need to have a wireless adapter 79 79
that works well with Kali 80 80
and you need to have that adapter connected to Kali 81 81
and connected to the target network. 82 82
So, I'm gonna hit enter here 83 83
and I'm gonna hit enter here, 84 84
and now if we go to the target machine 85 85
and run the same command arp -a, 86 86
you're gonna see that the MAC address now 87 87
for the router is different than what it was, 88 88
and this is the MAC address of the Kali machine. 89 89
So right now, this window's machine 90 90
thinks the router is at this MAC address 91 91
and every time it needs to send a request 92 92
it will send it to this MAC address, 93 93
which means that they will be sent 94 94
to this computer right here. 95 95
Now, this computer is not a router so when it gets requests, 96 96
it's actually going to stop them from flowing 97 97
and going to the router. 98 98
This is a security feature in Linux. 99 99
So, you need to enable port forwarding so that 100 100
this computer would allow packets to flow through it 101 101
just like a router. 102 102
Now to enable port forwarding, 103 103
we're gonna do echo one to proc/sys/net/ipv4/ip_forward, 104 104
and as you can see this command 105 105
gets executed with no issues. 106 106
And right now this computer 107 107
will still have its internet access, 108 108
so we can go and browse any website we want, 109 109
but all these requests are not going directly to the router, 110 110
but they are going to this computer first 111 111
and then this computer is forwarding them to the router, 112 112
as shown in this diagram, and then when the response's 113 113
come back they are gonna go to the hacker first, 114 114
and then they go to the victim. 115 115
So as you can see a very simple tool, 116 116
it allows us to redirect the flow of data 117 117
so it flows through our computer 118 118
allowing us to become the man in the middle, 119 119
and once we're the man in the middle, 120 120
we can inject code in the browser of the target. 121 121
We can steal usernames, passwords, 122 122
see all the information that the person sends and receives, 123 123
replace downloaded files with Trojans and much much more.