1 1 00:00:00,630 --> 00:00:02,160 When it comes to networking, 2 2 00:00:02,160 --> 00:00:05,883 you've probably heard of the term MAC address a lot. 3 3 00:00:06,740 --> 00:00:08,060 So in this lecture, 4 4 00:00:08,060 --> 00:00:10,820 I'm gonna cover what do we mean by MAC address, 5 5 00:00:10,820 --> 00:00:13,993 what it's used for, and how to change it. 6 6 00:00:13,993 --> 00:00:15,632 (dramatic music) 7 7 00:00:15,632 --> 00:00:18,215 (loud banging) 8 8 00:00:20,100 --> 00:00:23,550 MAC address stands for Media Access Control, 9 9 00:00:23,550 --> 00:00:26,850 it's a permanent, physical, and unique address 10 10 00:00:26,850 --> 00:00:29,170 assigned to network interfaces 11 11 00:00:29,170 --> 00:00:31,590 by the device manufacturer. 12 12 00:00:31,590 --> 00:00:33,560 So whether you have a wireless card, 13 13 00:00:33,560 --> 00:00:35,990 or a wired, or Ethernet card, 14 14 00:00:35,990 --> 00:00:38,000 each one of these network cards 15 15 00:00:38,000 --> 00:00:41,960 come with a specific address that is unique to this card. 16 16 00:00:41,960 --> 00:00:44,490 So there is no two devices in the world 17 17 00:00:44,490 --> 00:00:46,690 that would have the same MAC address. 18 18 00:00:46,690 --> 00:00:49,970 And this address will always be the same 19 19 00:00:49,970 --> 00:00:51,720 to this specific device, 20 20 00:00:51,720 --> 00:00:54,040 even if you unplug it from your computer, 21 21 00:00:54,040 --> 00:00:55,890 connect it to another computer, 22 22 00:00:55,890 --> 00:01:00,343 then this network device will always have the same address. 23 23 00:01:01,570 --> 00:01:04,160 So you might already know that the IP address 24 24 00:01:04,160 --> 00:01:08,070 is used in the internet to identify computers, 25 25 00:01:08,070 --> 00:01:11,900 and communicate between devices on the internet. 26 26 00:01:11,900 --> 00:01:14,850 The MAC address is used within the network 27 27 00:01:14,850 --> 00:01:19,423 to identify devices and transfer data between devices. 28 28 00:01:20,360 --> 00:01:22,730 So each piece of data or packet 29 29 00:01:22,730 --> 00:01:24,660 that is sent within the network 30 30 00:01:24,660 --> 00:01:28,900 contains a source MAC and a destination MAC. 31 31 00:01:28,900 --> 00:01:31,120 Therefore, this packet would flow 32 32 00:01:31,120 --> 00:01:33,863 from the source MAC to the destination MAC. 33 33 00:01:35,010 --> 00:01:38,440 So because this is a physical unique address 34 34 00:01:38,440 --> 00:01:41,710 to each interface, to each network device, 35 35 00:01:41,710 --> 00:01:45,010 and because it is used to identify devices, 36 36 00:01:45,010 --> 00:01:48,673 then changing it will make you anonymous on the network. 37 37 00:01:49,670 --> 00:01:52,460 Not only that, but the MAC address is often used 38 38 00:01:52,460 --> 00:01:55,660 by filters to prevent or allow devices 39 39 00:01:55,660 --> 00:01:57,160 to connect to networks, 40 40 00:01:57,160 --> 00:02:00,040 and do specific tasks on the network. 41 41 00:02:00,040 --> 00:02:02,080 So being able to change your MAC address 42 42 00:02:02,080 --> 00:02:04,080 to another device's MAC address 43 43 00:02:04,080 --> 00:02:06,870 will allow you to impersonate this device 44 44 00:02:06,870 --> 00:02:08,830 and allow you to do things 45 45 00:02:08,830 --> 00:02:11,040 that you might not be able to do. 46 46 00:02:11,040 --> 00:02:13,280 So you'd be able to bypass filters, 47 47 00:02:13,280 --> 00:02:16,450 or connect to networks that only specific devices 48 48 00:02:16,450 --> 00:02:19,290 with specific MAC addresses can connect to, 49 49 00:02:19,290 --> 00:02:22,333 and you will also be able to hide your identity. 50 50 00:02:23,500 --> 00:02:26,300 Now changing the MAC address is very, very simple, 51 51 00:02:26,300 --> 00:02:28,313 so let me show you how to do that. 52 52 00:02:29,530 --> 00:02:33,540 First of all, I'm going to use the ifconfig command 53 53 00:02:33,540 --> 00:02:36,250 to list all the network interfaces 54 54 00:02:36,250 --> 00:02:38,783 available on my Kali machine. 55 55 00:02:39,890 --> 00:02:43,540 What I mean by network interface is any device 56 56 00:02:43,540 --> 00:02:46,360 that allow us to connect to a network. 57 57 00:02:46,360 --> 00:02:48,610 So an example is a Wi-Fi card, 58 58 00:02:48,610 --> 00:02:51,223 or an Ethernet card, and so on. 59 59 00:02:52,450 --> 00:02:56,030 So you can see first of all we have eth0, 60 60 00:02:56,030 --> 00:03:00,750 and this is a virtual interface created by virtual box 61 61 00:03:00,750 --> 00:03:03,993 when we set Kali to use iNet network. 62 62 00:03:04,850 --> 00:03:08,890 So you can see the interface name is eth0, 63 63 00:03:08,890 --> 00:03:11,990 you can see it has an IP address because like I said, 64 64 00:03:11,990 --> 00:03:13,780 it's connected to a network. 65 65 00:03:13,780 --> 00:03:17,723 So if we go here, we can see it saying Wired Connected. 66 66 00:03:18,570 --> 00:03:22,350 So this is the interface that represents the wired network 67 67 00:03:22,350 --> 00:03:24,420 that Kali is connected to, 68 68 00:03:24,420 --> 00:03:26,803 which is actually a virtual NAT network. 69 69 00:03:27,790 --> 00:03:30,950 You can also see the netmask, the broadcast, 70 70 00:03:30,950 --> 00:03:34,030 and a really important piece of information, 71 71 00:03:34,030 --> 00:03:35,453 which is the ether. 72 72 00:03:36,320 --> 00:03:41,203 This is the MAC address of this virtual interface. 73 73 00:03:42,330 --> 00:03:44,150 Now, you can see similar information 74 74 00:03:44,150 --> 00:03:49,150 for my other two interfaces, the lo and the lan0. 75 75 00:03:49,370 --> 00:03:53,040 The only thing is you can see for both of these interfaces, 76 76 00:03:53,040 --> 00:03:56,210 we do not have an IP address. 77 77 00:03:56,210 --> 00:03:57,870 And the main reason for that 78 78 00:03:57,870 --> 00:04:00,670 is because none of these interfaces 79 79 00:04:00,670 --> 00:04:02,453 is connected to a network. 80 80 00:04:03,390 --> 00:04:07,780 Now lo is the default interface created by Linux, 81 81 00:04:07,780 --> 00:04:11,810 and lan0 is my real wireless adapter, 82 82 00:04:11,810 --> 00:04:15,710 so I can use it to connect to Wi-Fi networks. 83 83 00:04:15,710 --> 00:04:18,530 But if I go on the network in here, 84 84 00:04:18,530 --> 00:04:21,150 you'll see Wi-Fi is not connected, 85 85 00:04:21,150 --> 00:04:24,170 because I actually didn't connect to any network, 86 86 00:04:24,170 --> 00:04:27,723 and that's why it does not have an IP address. 87 87 00:04:29,420 --> 00:04:32,010 Now, this doesn't matter because what we want to do 88 88 00:04:32,010 --> 00:04:34,740 is to just change the MAC address, 89 89 00:04:34,740 --> 00:04:38,250 which again, is shown here under the ether part, 90 90 00:04:38,250 --> 00:04:41,863 so similar to what you're seeing here for eth0. 91 91 00:04:42,880 --> 00:04:45,960 Now, in order to change any of the values 92 92 00:04:45,960 --> 00:04:47,510 that you see in here, 93 93 00:04:47,510 --> 00:04:51,093 you have to first disable the interface. 94 94 00:04:52,120 --> 00:04:56,200 So in this example, we want to change the MAC address, 95 95 00:04:56,200 --> 00:04:58,820 so that is represented by the ether 96 96 00:04:58,820 --> 00:05:00,913 and the value is right here. 97 97 00:05:01,880 --> 00:05:04,870 So in order to disable an interface, 98 98 00:05:04,870 --> 00:05:09,480 we're gonna do ifconfig followed by the interface name, 99 99 00:05:09,480 --> 00:05:14,480 which is lan0 in my example, followed by down to disable it. 100 100 00:05:15,670 --> 00:05:17,700 Now, if I hit Enter, you'll see 101 101 00:05:17,700 --> 00:05:19,730 the command runs with no errors, 102 102 00:05:19,730 --> 00:05:23,310 so it means that it got executed properly. 103 103 00:05:23,310 --> 00:05:25,320 And the next thing that we need to do, 104 104 00:05:25,320 --> 00:05:28,750 is to change the option that we want to change. 105 105 00:05:28,750 --> 00:05:31,910 And in this example, we want to change the ether, 106 106 00:05:31,910 --> 00:05:33,963 which is the MAC address. 107 107 00:05:34,800 --> 00:05:37,283 So first, we're gonna type ifconfig, 108 108 00:05:38,260 --> 00:05:41,350 we're gonna type the interface that we want to change, 109 109 00:05:41,350 --> 00:05:45,960 one of its options, then we're gonna type 110 110 00:05:45,960 --> 00:05:49,440 the option that we want to change. 111 111 00:05:49,440 --> 00:05:53,100 And what we want to change is the hardware address, 112 112 00:05:53,100 --> 00:05:56,323 so we're gonna do hw ether. 113 113 00:05:57,380 --> 00:05:59,420 Then we're gonna give it the address 114 114 00:05:59,420 --> 00:06:02,520 that we want to change the MAC address to. 115 115 00:06:02,520 --> 00:06:07,520 So for example, I'm gonna use 00:11:22:33:44:55. 116 116 00:06:10,840 --> 00:06:12,670 Very, very simple command, 117 117 00:06:12,670 --> 00:06:16,210 we're doing ifconfig lan0 to select the interface 118 118 00:06:16,210 --> 00:06:18,410 that we want to change its option, 119 119 00:06:18,410 --> 00:06:21,160 we wanna set the hardware address, 120 120 00:06:21,160 --> 00:06:25,670 and we wanna set this address to this specific address. 121 121 00:06:25,670 --> 00:06:27,810 So you can use any address that you want, 122 122 00:06:27,810 --> 00:06:30,370 following the same format shown here. 123 123 00:06:30,370 --> 00:06:33,963 Just make sure your address starts with 00. 124 124 00:06:34,930 --> 00:06:37,270 So I'm gonna hit Enter and again, 125 125 00:06:37,270 --> 00:06:39,020 we don't see any error messages, 126 126 00:06:39,020 --> 00:06:42,470 so it means the command got executed properly. 127 127 00:06:42,470 --> 00:06:46,560 And finally, we just need to enable the interface 128 128 00:06:46,560 --> 00:06:50,360 because we disabled it, by doing, ifconfig lan0 down, 129 129 00:06:50,360 --> 00:06:55,360 so we just need to do, ifconfig lan0 up, to enable it. 130 130 00:06:57,840 --> 00:06:59,881 Now the interface is enabled, 131 131 00:06:59,881 --> 00:07:02,393 and if we do ifconfig again, 132 132 00:07:03,650 --> 00:07:06,610 and look at the ether part in here, 133 133 00:07:06,610 --> 00:07:09,310 you can see that it is changed 134 134 00:07:09,310 --> 00:07:11,953 to the MAC address that we specified. 135 135 00:07:13,970 --> 00:07:16,840 Now, this is done, and your MAC address has changed. 136 136 00:07:16,840 --> 00:07:20,700 Now, you can go ahead and start using the interface 137 137 00:07:20,700 --> 00:07:23,700 and it'll appear to have this MAC address 138 138 00:07:23,700 --> 00:07:26,290 instead of its original MAC address. 139 139 00:07:26,290 --> 00:07:30,543 And like I said, this can be useful in so many scenarios. 140 140 00:07:32,050 --> 00:07:35,670 Now, keep in mind, the MAC address will revert back 141 141 00:07:35,670 --> 00:07:39,520 to the original one once you restart the computer, 142 142 00:07:39,520 --> 00:07:43,170 because we're only changing the MAC address in memory, 143 143 00:07:43,170 --> 00:07:47,070 we're not really changing the physical MAC address. 144 144 00:07:47,070 --> 00:07:49,970 But if your MAC address is resetting 145 145 00:07:49,970 --> 00:07:53,140 to the original one without restarting, 146 146 00:07:53,140 --> 00:07:54,840 then something is going wrong. 147 147 00:07:54,840 --> 00:07:58,240 And it's probably happening because your network manager 148 148 00:07:58,240 --> 00:08:00,970 is resetting the MAC address. 149 149 00:08:00,970 --> 00:08:03,130 Not everybody will face this issue, 150 150 00:08:03,130 --> 00:08:05,730 so I'm not gonna cover it in this lecture, 151 151 00:08:05,730 --> 00:08:07,520 but if you face this issue, 152 152 00:08:07,520 --> 00:08:10,360 if your MAC address goes back to the original one 153 153 00:08:10,360 --> 00:08:12,690 without restarting the computer, 154 154 00:08:12,690 --> 00:08:14,860 then check out the YouTube video 155 155 00:08:14,860 --> 00:08:16,950 in the resources of this lecture, 156 156 00:08:16,950 --> 00:08:19,543 it'll show you how to fix this issue.