00:02 Good day students.

00:15 My name is Ilughuhu Stella

00:17 I'll be taking you information technology.

00:20 A topic for today is computer virus.

00:24 But before we go into the lesson proper,

00:26 let's look at the aims and the objective of the lesson.

00:30 One, you should be able to define,

00:33 at the end of the lesson,

00:34 you should be able to define computer virus,

00:37 stay some symptoms of the virus.

00:39 You should be able to mention the advantages

00:41 and disadvantages of computer virus,

00:44 give example of virus and you should be able to list

00:48 some of the antiviruses that can be used.

00:51 Now, what is computer virus?

00:55 A computer virus is a self-replicating piece

00:58 of computer code that can partially

01:01 or fully attach itself to computer virus or application

01:05 and cause a work to the computer.

01:08 Now, what do we mean by this?

01:10 A computer virus have two basic characteristics.

01:15 The first one is it replicates itself to another file.

01:20 And then the second one is it's attached itself to a file.

01:28 Now, computer virus can perform tags

01:32 which the user does not want it to perform.

01:36 That means it goes ahead to do work

01:38 that the user does not really want at that particular time.

01:44 Now, some of this work are it can override

01:48 on the hard disk or format hard disk

01:54 or it will allow your booting sector to boot

01:59 and delete it can also delete so many files

02:02 by this rendering the machine in or pretty boot.

02:06 Computer virus are also programs that can copy itself

02:12 without the permission or the knowledge of the user.

02:15 Just like I said, when I was trying to introduce the topic,

02:20 the computer virus go ahead without the permission

02:23 of the user.

02:24 Just write on your applications or your files

02:30 without the knowledge of the user.

02:33 A virus can only spread from one computer to another

02:37 when its host is taking to the infected computer.

02:41 Now, once a virus or once a file is being affected by virus,

02:47 automatically that virus becomes a virus.

02:51 So, if you take it to another system,

02:54 definitely that system will be infected with virus.

02:58 For example, some of the movable,

03:05 some of the files that can carry the virus are

03:09 removable medium such as floppy disk,

03:12 your CD, your UBS drive, and so on.

03:18 Now, this will take us to types of computer virus.

03:22 Now, there are numerous types of computer virus,

03:25 but for this lesson, we'll be categorizing them

03:29 into six categories.

03:31 The first one will be the boot sector virus.

03:36 Now, what this virus does to your system is,

03:40 once your system have a boot virus, boot virus sectors,

03:46 what happened is that the headaches

03:49 will not be able to boost.

03:52 All of you know that once you put on your system,

03:55 the first thing that happened to your computer

03:57 is for the system to boot itself automatically.

04:01 But once you discover that your system cannot boot,

04:04 then you should suspect that the system

04:07 have a boot sector virus.

04:11 The second one is the file virus.

04:14 Now, what this one does is that this kind of virus

04:19 infects the applications.

04:21 The infected applications spread the virus

04:23 by infecting associated documents and other applications

04:28 whenever they are open or wrong.

04:30 Like I said earlier along, once a file is being affected,

04:35 automatically it has become a virus.

04:40 So once a file that has been affected

04:42 has been opened or wrong in the system,

04:45 automatically it spreads the virus across.

04:49 The next one is the microvirus.

04:54 This virus affects Microsoft application

04:57 such as your world, Excel, your Microsoft world,

05:02 and all that, Microsoft application.

05:06 The next one is multiple type virus.

05:12 Now, this virus affects both your files

05:16 and your boot sector.

05:18 You know, earlier on I said the boot sector

05:20 is when it's been affected, your system will not boot.

05:25 So this multi-virus, this multi-patter virus

05:28 affects both your files and your boot sector.

05:33 The next one is polymorphic virus.

05:36 This changes code.

05:39 Whenever it is passed to another machine.

05:43 So this one, you know, where you have a code on your system,

05:47 it's automatically changed the code without your knowledge.

05:51 Maybe sometimes it just discover you want to open a file

05:54 and then maybe you use the code to close the file

05:57 and then you try to use it just discover that it's not responding.

06:01 Maybe telling you it's invalid.

06:03 So automatically you should know

06:05 that you already have what a polymorphic virus.

06:09 The next one is tillate virus.

06:12 This virus hide its present by making an effective file

06:18 appear not infected.

06:20 So sometimes when your system has this virus,

06:24 you may not even know that the system has a virus.

06:28 Just like somebody that has a virus

06:30 and then you're still working about normally,

06:32 you think that it's not sick,

06:34 but inside him is not showing anything,

06:37 but that inside he knew that something is wrong,

06:40 but it can't really say what is happening.

06:42 So the same way this tillate virus does to your system.

06:47 Once the system has a still tillate virus,

06:50 you sometimes you don't really know.

06:52 Except if there is a powerful anti-virus in your system

06:57 that will make you know that yes,

06:59 there's a virus, this virus is being,

07:01 your system is being affected with this virus.

07:06 Now this will take us to the advantages

07:09 and computer virus and disadvantages.

07:13 Now you tend to ask me why advantages,

07:16 something that is causing havoc to your system,

07:21 where it is believing life that anything that has advantages

07:25 must also have disadvantages.

07:28 So one of the advantages of the computer virus is that

07:32 it's led to the development of and the virus.

07:37 And you know for the person that develops it

07:41 on his own path, he wants to make money from it.

07:44 So by the time he sells it out,

07:46 he makes money from it.

07:48 Also, when your system is being,

07:53 when you have problems with your system,

07:56 you have to take it to the computer engineer.

07:59 So by doing that, the computer engineer on the other end

08:03 is also making money out of it.

08:06 So if you don't want to spend on necessary money,

08:09 then you have to protect your system from having virus.

08:13 So this takes us to the advantages of computer virus.

08:17 So one, it can remain not detected.

08:24 Like I said, in the still rate virus.

08:27 Now your system may have a still rate virus

08:30 and yet you don't show any symptoms.

08:33 And so you feel your computer is not being affected.

08:37 So it remains undetected.

08:40 Now, two, it can cause lots of data,

08:44 make your computer to crash and display disturbing messages.

08:48 Sometimes you just open your system,

08:50 you begin to see if at that that you did not call for.

08:54 And once you see this one, you should know that your system

08:57 already have a virus.

09:00 Examples of computer virus, there are numerous of them.

09:05 But we just look at some of them.

09:07 Like sleep virus, logic bomb virus, laboratory virus,

09:12 Christmas virus, Jerusalem virus,

09:17 and there are lots more of them.

09:19 All right.

09:22 So we would like, before I round up this section,

09:26 I would like to summarize what we have said so far.

09:29 Like we said, computer virus is a self-replicating code

09:35 that can fully or partially attach itself

09:38 to the computer virus.

09:39 Okay, before we, I round up this class,

09:42 I would like to evaluate you with this question.

09:45 One, mention types of computer virus.

09:49 Two, define computer virus.

09:52 Okay, so we meet in the next class.

09:55 I remain your teacher, Ilubu Estella.

09:59 Thank you.

10:00 (upbeat music)