1 1 00:00:00,480 --> 00:00:01,890 Clickjacking. 2 2 00:00:01,890 --> 00:00:03,750 In this lesson, we are going to talk about 3 3 00:00:03,750 --> 00:00:05,850 the dangers of clickjacking. 4 4 00:00:05,850 --> 00:00:07,950 Clickjacking is a type of hijacking account 5 5 00:00:07,950 --> 00:00:10,770 that forces a user to unintentionally click a link 6 6 00:00:10,770 --> 00:00:14,010 that's embedded in or hidden by other webpage elements. 7 7 00:00:14,010 --> 00:00:15,930 For instance, let's say I was playing a video game 8 8 00:00:15,930 --> 00:00:17,880 and there's a big play button, and I don't see 9 9 00:00:17,880 --> 00:00:20,190 that behind that, there's actually a pay button 10 10 00:00:20,190 --> 00:00:21,990 and if I click that link for play, 11 11 00:00:21,990 --> 00:00:23,580 I'm not actually clicking the play button. 12 12 00:00:23,580 --> 00:00:26,220 I'm clicking this hidden layer that says pay 13 13 00:00:26,220 --> 00:00:27,750 and that's going to charge me. 14 14 00:00:27,750 --> 00:00:30,000 This is the idea of using clickjacking. 15 15 00:00:30,000 --> 00:00:32,220 Clickjacking is used when a victim clicks the link, 16 16 00:00:32,220 --> 00:00:33,720 they can be redirected to what appears 17 17 00:00:33,720 --> 00:00:35,400 to be a legitimate page as well. 18 18 00:00:35,400 --> 00:00:36,660 For instance, I click on something, 19 19 00:00:36,660 --> 00:00:38,610 it takes me something that looks like a login page. 20 20 00:00:38,610 --> 00:00:41,250 I enter my username and password, and low and behold, 21 21 00:00:41,250 --> 00:00:42,840 I didn't really log into my site. 22 22 00:00:42,840 --> 00:00:44,850 I just gave them my username and password. 23 23 00:00:44,850 --> 00:00:46,680 This is another form of clickjacking 24 24 00:00:46,680 --> 00:00:49,080 and another reason you have to be on the lookout for it. 25 25 00:00:49,080 --> 00:00:50,880 Now, clickjacking is made possible 26 26 00:00:50,880 --> 00:00:54,030 because of the use of iframes within HTML. 27 27 00:00:54,030 --> 00:00:56,340 Essentially, because of these iframes that are allowed 28 28 00:00:56,340 --> 00:00:58,230 within HTML, you can actually have 29 29 00:00:58,230 --> 00:01:00,780 invisible iframes that's accepting the values 30 30 00:01:00,780 --> 00:01:02,010 when you're inputting your credentials 31 31 00:01:02,010 --> 00:01:04,140 even though you don't see it on the screen. 32 32 00:01:04,140 --> 00:01:05,490 It's really, really tricky, 33 33 00:01:05,490 --> 00:01:08,400 but it is something that can be done through clickjacking. 34 34 00:01:08,400 --> 00:01:10,170 Now, one way to prevent clickjacking 35 35 00:01:10,170 --> 00:01:12,150 is by using frame busting. 36 36 00:01:12,150 --> 00:01:14,190 Now, frame busting is a technique that removes 37 37 00:01:14,190 --> 00:01:16,102 the malicious iframe loaded on the site 38 38 00:01:16,102 --> 00:01:19,140 by forcing your page to the top frame 39 39 00:01:19,140 --> 00:01:21,630 'cause essentially, think about this like layers. 40 40 00:01:21,630 --> 00:01:23,730 If they have a clickjacking on your site 41 41 00:01:23,730 --> 00:01:25,650 and they have an invisible layer on top, 42 42 00:01:25,650 --> 00:01:26,820 people are entering it on there 43 43 00:01:26,820 --> 00:01:28,680 even though they think they're on your site. 44 44 00:01:28,680 --> 00:01:31,080 By taking your site and forcing it to the top, 45 45 00:01:31,080 --> 00:01:32,545 that's going to make sure they're always inputting data 46 46 00:01:32,545 --> 00:01:36,120 in your site and not on the clickjack site. 47 47 00:01:36,120 --> 00:01:37,410 Now, one of the ways to do this 48 48 00:01:37,410 --> 00:01:39,990 is by using just a simple bit of JavaScript. 49 49 00:01:39,990 --> 00:01:42,480 For instance, if top does not equal self, 50 50 00:01:42,480 --> 00:01:45,510 then self location equals top location. 51 51 00:01:45,510 --> 00:01:47,280 This takes your layer and puts it on the top 52 52 00:01:47,280 --> 00:01:48,780 to prevent clickjacking. 53 53 00:01:48,780 --> 00:01:50,190 Now, this will only work against 54 54 00:01:50,190 --> 00:01:51,750 the most simple framing abuse, 55 55 00:01:51,750 --> 00:01:53,610 but it is something good to put in there. 56 56 00:01:53,610 --> 00:01:56,220 There are more advanced iframe attacks that could use 57 57 00:01:56,220 --> 00:01:59,010 more advanced countermeasures using JavaScript as well. 58 58 00:01:59,010 --> 00:02:01,710 For instance, you could use X-Frame-Options. 59 59 00:02:01,710 --> 00:02:04,650 If you set your X-Frame-Options and set them to deny, 60 60 00:02:04,650 --> 00:02:06,000 this is actually a better strategy 61 61 00:02:06,000 --> 00:02:07,740 to protect against clickjacking. 62 62 00:02:07,740 --> 00:02:09,690 Now, when you do this, you have to make sure 63 63 00:02:09,690 --> 00:02:11,070 that this is in the header 64 64 00:02:11,070 --> 00:02:13,200 and deploy to every page in your domain. 65 65 00:02:13,200 --> 00:02:15,270 If you don't do that, then the clickjackers 66 66 00:02:15,270 --> 00:02:16,260 still have a way in 67 67 00:02:16,260 --> 00:02:18,683 and they can still take advantage of your customers.