1 00:00:00,150 --> 00:00:03,030 So this is going to be a short introduction to the. 2 00:00:04,750 --> 00:00:06,980 So let me display the contents of that file. 3 00:00:09,820 --> 00:00:13,120 Shadow, I figured it their. 4 00:00:14,080 --> 00:00:16,400 So since I'm the road user. 5 00:00:16,450 --> 00:00:18,010 I have the permissions. 6 00:00:19,060 --> 00:00:21,010 I said to see Shardul. 7 00:00:27,310 --> 00:00:29,530 I'm sorry, I did not like the cat comment. 8 00:00:31,970 --> 00:00:40,840 So let's discuss the contents of the T-shirt so you can see the root user and there are some other services, 9 00:00:40,850 --> 00:00:42,490 you can see the second Flagstar. 10 00:00:42,740 --> 00:00:52,340 So if any system service, order service has the star, it means that we cannot login to the system 11 00:00:52,340 --> 00:00:55,660 as the service or that the one process. 12 00:00:55,670 --> 00:00:56,010 Right. 13 00:00:56,180 --> 00:00:58,030 There is no login for these services. 14 00:00:58,850 --> 00:01:03,040 And if you scroll down, you have that Nickey and the nickel. 15 00:01:03,320 --> 00:01:06,710 So these are the two users on my Linux system. 16 00:01:09,320 --> 00:01:15,040 So first, I'm going to explain this syntax, and it will be to be easy for you to understand. 17 00:01:15,320 --> 00:01:17,990 First one is the user name and the second filter. 18 00:01:18,000 --> 00:01:27,060 You have this Longland to some data and this is the end password for your Nekesa. 19 00:01:28,040 --> 00:01:30,110 So this is the encrypted password. 20 00:01:31,070 --> 00:01:39,260 And the third column is the number of deaths you have created this unique user from the January 1st, 21 00:01:39,260 --> 00:01:39,980 1970. 22 00:01:40,280 --> 00:01:49,310 So there is a time called Unix Epoch Time, and from that time it will be considered after this eighteen 23 00:01:49,310 --> 00:01:50,950 thousand thirty deaths. 24 00:01:51,710 --> 00:01:54,150 I have created this user, Nikkie. 25 00:01:54,380 --> 00:02:04,290 So if I add eighteen thousand thirty four to the January 1st, 1970, and from those many days I have, 26 00:02:04,340 --> 00:02:08,470 I will get a date on which I have created this user, Nickey. 27 00:02:08,780 --> 00:02:18,650 So I have created this user today only so does the fourth column is Dero Geto means that we need to 28 00:02:18,650 --> 00:02:22,200 wait for some more this to change the password again. 29 00:02:22,220 --> 00:02:30,200 So if I change this password now today, if I have the value of it, I need to wait for five days to 30 00:02:30,500 --> 00:02:31,820 change my password again. 31 00:02:32,120 --> 00:02:34,920 Since I have zero, I can change it anytime. 32 00:02:35,420 --> 00:02:38,340 So this 999 is maximum pasturage. 33 00:02:38,390 --> 00:02:44,170 That means that after these many days I need to update my password. 34 00:02:44,600 --> 00:02:48,260 So it's like life time and this seven means. 35 00:02:50,110 --> 00:02:57,830 The number of days before I get notification that my passport is going to be excellent, so I have to 36 00:02:57,830 --> 00:03:03,760 wait nine nine nine nine nine, so on the nine nine nine nine second day, I will get a notification 37 00:03:03,760 --> 00:03:05,670 that your passport is going to be expired. 38 00:03:05,680 --> 00:03:06,370 Please change. 39 00:03:07,360 --> 00:03:15,190 So in the same way, the user contents are also sim nickel and then their password and the one eight 40 00:03:15,190 --> 00:03:15,910 five three six. 41 00:03:16,210 --> 00:03:21,340 So I helped create the Nikil and today I created this nickel user. 42 00:03:22,300 --> 00:03:30,190 So it means that there is one day difference, that there is one different and Geto means the minimum 43 00:03:30,190 --> 00:03:30,770 password. 44 00:03:30,910 --> 00:03:34,090 It it means that I don't need to wait for anything. 45 00:03:34,090 --> 00:03:36,820 I can just simply change the password at any time. 46 00:03:37,670 --> 00:03:41,440 Nine nine nine nine is the maximum password explained. 47 00:03:43,110 --> 00:03:48,010 So after these days, my password will expire and also I also get to work. 48 00:03:48,060 --> 00:03:48,450 OK. 49 00:03:48,960 --> 00:03:55,020 And the sun is up before the founders of this password, I get a notification that I need to know password. 50 00:03:55,200 --> 00:04:02,160 So after these immigrants, we have know that that means the expiration date and post expiration and 51 00:04:02,160 --> 00:04:02,580 so on. 52 00:04:03,090 --> 00:04:08,040 Since we our password does not get did not expect, we have done all things. 53 00:04:08,610 --> 00:04:10,630 So that's what you need to know what the issues are. 54 00:04:11,160 --> 00:04:18,510 And one more what you need to know about this fight is if you have the right permissions, you can dump 55 00:04:18,510 --> 00:04:26,690 this hash and you can try to crack with the tools like Don Draper or Craxton or any other tools. 56 00:04:28,290 --> 00:04:37,890 So we know when you put the password for your Linux system, it will be very faster to crack this hashes 57 00:04:38,070 --> 00:04:39,880 and you get the plain text format. 58 00:04:40,660 --> 00:04:50,450 That's why you need to check that it gets to the original user had access to a tee shot of it or not. 59 00:04:50,760 --> 00:04:55,240 If they have access, they can just dump this file and try to catch the password. 60 00:04:55,950 --> 00:05:03,030 That's why the one security mechanism you need to implement is use the strongest passwords as possible.