WEBVTT 1 00:01.970 --> 00:02.600 Welcome back. 2 00:02.840 --> 00:10.640 In this lesson, we are going to explore how to patch the things to always show the good message, even 3 00:10.640 --> 00:13.370 though you enter the wrong username or serial. 4 00:13.520 --> 00:15.140 So you can try this on your own. 5 00:15.140 --> 00:19.010 Pause the video and later on check the solution. 6 00:20.810 --> 00:22.100 Okay, I hope you have tried that. 7 00:22.100 --> 00:24.110 So let's see how to solve this. 8 00:24.470 --> 00:27.380 We run this now and let the thing pop up. 9 00:28.310 --> 00:31.580 Now we enter any wrong username. 10 00:33.820 --> 00:38.500 And we enter any serial, not the correct serial. 11 00:38.500 --> 00:40.750 But it will still when you click on check. 12 00:41.830 --> 00:42.640 Click run. 13 00:43.030 --> 00:45.520 It will still show the sorry. 14 00:45.520 --> 00:46.090 Don't give up. 15 00:46.510 --> 00:50.890 So we want it to show the good message no matter whatever we enter. 16 00:51.850 --> 00:53.200 So let's see how to do that. 17 00:53.290 --> 00:54.220 Click check again. 18 00:55.090 --> 00:58.090 And now it hits our breakpoint. 19 00:58.900 --> 01:00.850 So we go to graph view. 20 01:02.440 --> 01:08.800 And then we will come down until this jump. 21 01:09.640 --> 01:18.040 And this is the place where it will decide whether to show the bad message on the left or to show 22 01:18.040 --> 01:19.570 the good message on the right. 23 01:19.570 --> 01:21.280 So we'll keep on. 24 01:21.670 --> 01:24.580 We'll put the breakpoint here and run over here. 25 01:25.060 --> 01:27.400 So run until it hits this breakpoint. 26 01:27.940 --> 01:29.620 Let's remove the breakpoint now. 27 01:30.610 --> 01:36.790 So as you can see here test - is checking whether - is zero. 28 01:37.360 --> 01:40.000 That means it is expecting - to be zero. 29 01:40.570 --> 01:48.400 But because it is not zero, therefore this jump will go to the left because JNE means jump not 30 01:48.400 --> 01:49.360 equal to zero. 31 01:49.960 --> 01:52.630 The easiest way to solve this is to NOP this. 32 01:52.630 --> 01:53.770 So I already put a comment. 33 01:53.770 --> 01:54.280 NOP this. 34 01:54.280 --> 01:55.510 So when you NOP 35 01:55.510 --> 02:00.760 this, no matter whatever the value of -, it doesn't matter. 36 02:00.760 --> 02:02.920 It will still go to the right when you NOP this. 37 02:03.490 --> 02:07.240 So let's now follow in this assembler and NOP this. 38 02:09.290 --> 02:13.070 Right-click, binary, fill with NOPs, click okay. 39 02:14.720 --> 02:16.310 So now we are going to patch it. 40 02:16.310 --> 02:22.520 So patch file, click patch and select a new name. 41 02:22.520 --> 02:25.910 Put dash one at the back here, click save. 42 02:27.570 --> 02:28.800 I've done it before. 43 02:29.430 --> 02:30.870 Okay, so now let's test it. 44 02:31.740 --> 02:33.090 Test our patched one. 45 02:34.530 --> 02:36.990 We can close this one first. 46 02:38.220 --> 02:40.710 And let's run our patched one. 47 02:44.760 --> 02:46.680 So we enter any user. 48 02:51.080 --> 02:52.310 And any serial. 49 02:53.720 --> 02:56.480 And we click check and it says great job. 50 02:56.480 --> 02:57.650 So we have solved it. 51 02:57.650 --> 02:58.970 Let's try another one. 52 02:58.970 --> 03:02.270 Any other serial and any other user. 53 03:09.890 --> 03:11.000 Also it shows great job. 54 03:11.000 --> 03:13.820 So this is a very, very simple software patch. 55 03:14.060 --> 03:15.830 So that's all for this video. 56 03:15.830 --> 03:17.360 Thank you for watching.