WEBVTT 00:00.960 --> 00:01.200 Okay. 00:01.240 --> 00:04.520 In the previous lecture, we covered the city command. 00:04.560 --> 00:04.880 Okay. 00:04.920 --> 00:10.640 Now it is time to download a sample txt file. 00:10.680 --> 00:11.120 Okay. 00:11.640 --> 00:14.000 So the sample txt file. 00:14.040 --> 00:17.600 Let me first explain how does it work. 00:17.640 --> 00:19.400 While we're trying to download something. 00:19.440 --> 00:19.880 Okay. 00:21.000 --> 00:30.880 Uh when it is a simple txt file, first we are trying to read the file from backdoor and then send it 00:31.000 --> 00:31.440 here. 00:31.840 --> 00:36.000 Here we will create a new file and write it okay. 00:36.040 --> 00:37.000 So very easy. 00:37.160 --> 00:40.640 So here we need to create a method for writing into a file. 00:42.640 --> 00:43.480 Let's do that. 00:43.720 --> 00:44.600 Give off. 00:44.920 --> 00:46.240 Write again. 00:46.840 --> 00:51.240 So here we need to provide um two thing. 00:51.280 --> 00:51.960 Okay. 00:52.000 --> 00:54.800 One of them is going to be the path. 00:54.840 --> 00:55.320 Okay. 00:55.880 --> 00:59.080 Where, uh, where do we want to save this? 00:59.400 --> 01:02.000 The other one is going to be the content. 01:02.040 --> 01:02.480 Okay. 01:05.160 --> 01:12.280 Content is the data that we read from a reverse vector and write it here. 01:12.320 --> 01:13.000 Okay. 01:13.080 --> 01:19.960 So while we're trying to open a file we use width keyword and then open method which is which come from 01:20.560 --> 01:22.720 with Python when you install the Python. 01:22.760 --> 01:23.520 Okay. 01:23.560 --> 01:29.360 And here let's first give the path where the file located. 01:29.360 --> 01:33.720 And then you need to provide the mode for the file. 01:34.040 --> 01:40.320 So I'm going to be giving a w b means writing as binary. 01:40.360 --> 01:41.360 Okay. 01:41.400 --> 01:45.760 And here we are going to alias this as something like file. 01:45.800 --> 01:46.400 Okay. 01:46.440 --> 01:55.360 So now we uh, we can do a lot of a lot of things with this file that we have. 01:55.360 --> 01:57.120 For example, I'm going to write this. 01:57.120 --> 02:01.130 So I use file dot Right. 02:01.810 --> 02:02.210 Okay. 02:02.530 --> 02:04.690 What do I want to write inside this file? 02:04.770 --> 02:09.770 I want to write the content inside this file. 02:09.770 --> 02:13.650 And at the end, I can return just the text. 02:13.650 --> 02:15.770 For example, let's. 02:17.890 --> 02:21.250 Give this that download successful. 02:28.290 --> 02:28.770 Okay. 02:29.690 --> 02:32.730 So this is the right method. 02:33.690 --> 02:38.010 Let's change this write method to something else like write file okay. 02:40.410 --> 02:41.410 And here. 02:45.570 --> 02:49.410 Uh, down here after we receive the result okay. 02:50.530 --> 02:52.450 We can check it here. 02:54.290 --> 03:05.690 If, if the command okay that we receive from user and the first one that user provide. 03:05.730 --> 03:08.130 For example, they write download something. 03:08.450 --> 03:18.210 If this is equal to this word like download, then let's do something. 03:18.370 --> 03:26.610 If it is equal to download then let's um we have the result here okay. 03:26.610 --> 03:27.930 Result variable. 03:27.930 --> 03:31.250 So I'm going to say result is equal to self. 03:34.770 --> 03:35.250 Dot. 03:37.490 --> 03:40.290 Write file which is a method that we just created. 03:40.450 --> 03:43.570 And here I'm going to give the second. 03:45.770 --> 03:51.010 Option from the thing user enter. 03:51.010 --> 03:56.370 And finally we give the result as content. 03:56.370 --> 03:59.050 So here we have the command okay. 03:59.090 --> 04:02.610 This command will create a list for me. 04:02.610 --> 04:07.930 The first one is going to be download and the second one is a name of a file. 04:07.970 --> 04:15.290 Okay, so we give the name of the file as a path here and the content is equal to result. 04:15.330 --> 04:16.970 What is this result? 04:17.010 --> 04:20.210 This result is something that come from backdoor. 04:21.370 --> 04:26.930 And at the end we can just print this result here. 04:26.930 --> 04:28.730 But if I use decode. 04:28.770 --> 04:33.490 So right here is not going to print that for me because it is a text. 04:33.490 --> 04:43.250 And we don't need to use decode with text but with other command it is going to show them as okay. 04:43.330 --> 04:44.210 Okay. 04:44.250 --> 04:45.850 So now it is completed. 04:45.850 --> 04:52.730 Let's go back to Backdoor in Windows Machine to handle this here too. 04:52.730 --> 05:01.100 So in here we are going to create a method named via read file Okay. 05:01.140 --> 05:03.500 Because here we're going to read file. 05:03.900 --> 05:06.340 So let's create that file here. 05:06.460 --> 05:07.460 That method here. 05:08.220 --> 05:13.260 And in here we're going to give only the path. 05:13.300 --> 05:13.740 Okay. 05:16.500 --> 05:20.540 So to read a file again we need to first open that file. 05:20.900 --> 05:26.380 I use open method and then give the path path. 05:27.700 --> 05:32.580 And the mode is going to be RB means read as binary. 05:33.100 --> 05:35.820 And let's alias this as a file. 05:36.300 --> 05:39.740 After we read it, we need to return. 05:40.580 --> 05:42.940 Okay so let's use return. 05:43.140 --> 05:47.060 We have the file dot read method that will. 05:47.100 --> 05:49.780 This will read the whole content. 05:49.940 --> 05:53.940 So now we have this method this function or method. 05:53.940 --> 05:57.380 Here we need to use it somewhere in here. 05:57.420 --> 05:58.420 Okay. 05:58.420 --> 06:04.260 So down here again I need to check this so I use live data. 06:04.580 --> 06:06.980 The first data okay we receive. 06:07.300 --> 06:11.820 If this is equal to to download. 06:15.020 --> 06:16.500 Okay download. 06:16.900 --> 06:21.020 Then then we can do something. 06:21.020 --> 06:29.500 For example we can read the second option that come from listener. 06:29.540 --> 06:30.420 Okay. 06:30.460 --> 06:35.460 So let's have this command result. 06:35.500 --> 06:38.140 It is equal to self dot. 06:38.180 --> 06:43.420 We have just created the read file method here. 06:43.820 --> 06:48.100 And then in here we are going to just give the data. 06:48.820 --> 06:51.460 And number one why data number one. 06:51.460 --> 06:57.660 Because then the first keyword or the first index from the list is download. 06:57.700 --> 07:04.660 So the user will enter for example download name of the file and the name of the file will be right 07:04.660 --> 07:05.260 in here. 07:05.580 --> 07:07.540 And then we will add it here. 07:07.900 --> 07:11.580 And then we will read that and then return it from here. 07:11.580 --> 07:15.780 And we give it to here it is, it will start to command result. 07:15.780 --> 07:20.620 And at the end we return the command result from here to listener. 07:20.660 --> 07:25.420 So let me save this and go back here. 07:26.540 --> 07:28.500 Try to run this program. 07:28.500 --> 07:30.500 It is waiting for incoming connection. 07:31.060 --> 07:35.340 And here again let's run this. 07:37.340 --> 07:41.500 So let's use dir method to see what is inside this okay. 07:42.140 --> 07:45.180 You may ask why it is showing this as binary. 07:45.180 --> 07:50.980 That is because I removed the dot decode from here from printing okay. 07:52.860 --> 07:57.500 And here you see we have a sample dot txt file okay. 07:57.540 --> 08:01.430 So I want to read this I want to download this file. 08:02.190 --> 08:02.990 Uh, here. 08:03.270 --> 08:03.670 Okay. 08:03.710 --> 08:06.310 For example, in here, inside this reverse factor. 08:06.350 --> 08:06.590 Okay. 08:06.590 --> 08:10.510 You see, right now here is the file I want to download that right here. 08:11.110 --> 08:13.830 So let's use download keyword. 08:15.870 --> 08:17.350 And then name of the file. 08:17.350 --> 08:18.310 What is the name of the file. 08:18.310 --> 08:20.110 It is sample dot txt. 08:20.470 --> 08:23.910 So sample dot txt hit enter. 08:24.310 --> 08:26.510 You see download is successful. 08:26.630 --> 08:27.910 And let's go back here. 08:27.910 --> 08:29.590 You see a new file is added. 08:29.750 --> 08:35.350 When I open that we have seen the data which is inside here. 08:35.350 --> 08:37.750 And let's go back to windows machine. 08:40.430 --> 08:41.950 And that is here. 08:42.070 --> 08:48.030 If I open this this is the same thing that is added on the Linux. 08:48.030 --> 08:58.870 So here now you have your backdoor program that is able to download files the files from victim computer. 08:58.910 --> 09:00.910 So thanks for watching.