Computer virus. Presentation on computer science on the topic: "Computer viruses and anti-virus programs" Computer viruses and anti-virus programs

: to familiarize students with the concept of a virus, an anti-virus program, types of viruses, modern anti-viruses, and methods of fighting viruses.

  • Developmental:
    • develop the ability to defend one’s point of view in a discussion, computer literacy, and cognitive activity.
  • Educational:
    •  cultivate attention, accuracy, and thrifty attitude towards software and PCs.

    Equipment:

    • Computer class
    • Projector
    • Software: electronic lecture ( Annex 1), Microsoft programs Power Point, Microsoft Excel, Microsoft Security, Avast
    • Flash card infected with a virus
    • Tokens with numbers

    Literature:

    • N.D. Ugrinovich Informatics. Basic course 7th grade. Moscow, BINOM, 2005
    • www.metod-kopilka.ru (presentation by teacher Zhuravlev A.A. MBOU Secondary School No. 3, Donetsk)
    • http://ru.wikipedia.org/
    • http://www.ctspi.ru/
    • http://informatika.sch880.ru/
    • http://www.leon4ik.com (cartoon)
    • Verbal (lecture, conversation-discussion).
    • Visual (electronic presentation, review of antiviruses).
    • Game (questioning students on the topic)

    During the classes

    1. Organizational moment

    2. Introduction of new material (electronic presentation is used).

    1. Historical information

    The first infection with the virus occurred in 1986 in the USA. A virus called “Brain” infected floppy disks, created by Pakistani programmer Alvi. In the USA alone, this virus infected over 18 thousand PCs.

    When they began to develop viruses, they were only of a research nature, but gradually this turned into a hostile attitude towards users.

    2. What are computer viruses?

    Computer viruses is a well-written program that can reproduce itself, copy itself without permission, spontaneously attach itself to other programs, and, unnoticed by users, embed its code into files, documents, Internet Web pages, and email messages.

    3. Signs of viruses

    1. Stopping or malfunctioning programs that were previously functioning.
    2. Slow PC
    3. Inability to boot OS
    4. Disappearance of files and folders or distortion of their contents.

    4. Why is a computer virus dangerous?

    After infecting a PC, the virus can become active (or wake up) and begin its malicious actions.

    Activation of the virus may be associated with some events; (For example):

    • Coming of a certain date
    • Starting the program
    • Opening a document

    5. Types of computer viruses

    Computer viruses are classified according to their habitat and degree of impact.

    By “degree of impact”

    • Non-hazardous
    – as a rule, these viruses clog the computer’s memory by reproducing and can perform minor mischief – play a melody embedded in them or show a picture;
  • Dangerous
    • – these viruses can create some disruptions in the functioning of the PC – crashes, reboots, PC freezes, slow computer operation, etc.;
  • Very dangerous
    • – dangerous viruses can destroy programs, erase important data, kill boot and system areas hard drive which can then be thrown away.

    Computer viruses by "habitat"

    • File viruses –
     are implemented into programs and are activated when they are launched. Once launched, an infected program can infect other files until the computer is turned off or rebooted. operating system.
  • Macro viruses –
    •  infection occurs when a document file is opened in a program window, unless the ability to execute macro commands (macros) is disabled in the program.
  • Network viruses –
    •  can be transmitted by computer networks your program code and run it on computers connected to this network. Network virus infection can occur when working with by email

    or when “traveling” on the World Wide Web.

    6. You need to know this

    If, when you go to a website, you receive a message that your computer is infected by one or more antiviruses, do not rush to agree to the proposed scan of your computer and installation of a free program for this purpose. Nowadays, so-called rogueware, false antivirus software, has become widespread, the purpose of which is to force the user to pay money for a paid version of supposedly high-quality antivirus software. If you agree to this setting, the program running on your computer will continue to “block and destroy” viruses, showing its “quality”. In reality, the program does nothing, but simply displays windows about detected viruses and offers to buy a paid version. According to Symantec, there are already tens of millions of computers in the United States on which more than 250 varieties of such rogue antivirus programs are installed.

    7. Dangerous viruses

    The spread of computer viruses (discussed on slide 11).

    8. A worldwide email virus epidemic has begun. May 5, 2000, when tens of millions of computers connected to the Internet received an email message with an attractive title I LOVE YOU. The message contained an attached file that was a virus. After the recipient read this message, the virus infected the computer and began to destroy the file system.

    9. How to protect yourself from viruses?

    For the purpose of preventive protection against computer viruses, it is not recommended to run programs, open documents and email messages received from dubious sources and not previously scanned by anti-virus programs.

    10. Antivirus programs

    Antivirus programs are the most effective in fighting computer viruses. Antivirus programs use constantly updated lists of known viruses, which include the name of the virus and its program code.

    If an anti-virus program detects a virus program code in any file, the file is considered infected with a virus and is subject to “treatment”, that is, the virus program code is removed from it.

    If treatment is impossible, the entire file is deleted

    11. The process of virus infection and file disinfection. (discussed on slides 16-17)

    12. Antivirus programs

    • Antivirus scanners
    , which, after launch, check files and RAM for viruses and ensure their neutralization.
  • Antivirus "watchmen"
    •  (monitors) are constantly in random access memory computer and ensure files are checked as they are loaded into RAM.

    The most effective antivirus programs in the fight against computer viruses are:

    • Kaspersky Lab Antivirus
    • Doctor Web
    • NOD 32
    • AVAST
    • Microsoft Security
    • Avira

    13. The most popular viruses last week. (slide 20) (Before the lesson, this data must be updated.)

    3. Conversation-discussion with students

    1. Who do you think creates computer viruses and why?
    2. What is better: a downloaded antivirus on the Internet or a licensed antivirus?

    (Each student must put forward his own hypothesis and defend his point of view)

    4. Review and comparative analysis Microsoft Security and Avast antiviruses. Treating a flash card using Microsoft Security antivirus.

    5. The conclusion of the lesson is carried out in the form of a game “Save the computer from viruses”

    Students are asked to answer 6 questions. For each correct answer, students receive a token with a number; if no one answers correctly, then the token is not issued. From the received tokens, students must add up a code and enter it into the computer (a sheet has previously been created in Microsoft Excel ( Appendix 2)).

    Questions:

    1. In what year did the first virus infection occur? (token 6)
    2. In what year did mass infection with the virus occur? (token 2)
    3. What was the name of the first computer virus? (token 3)
    4. What is the most effective way to fight viruses? (token 5)
    5. Types of viruses (token 1)
    6. Types of antiviruses (token 4)

    Homework

    clause 1.7, notes in notebooks

    At the end of the lesson, students are invited to watch the cartoon The Thunderstorm (episode 24) from the Pochemuchka series.


    2 What is a virus? A computer virus is a program that, when executed, can spread without human intervention. Signs of infection: slowdown of the computer, rebooting or freezing of the computer, incorrect operation of the OS or application programs, changes in the length of files, the appearance of new files, a decrease in the amount of RAM, sending messages without the author’s knowledge




    4 What do viruses infect? Program viruses – *. exe, *. com boot sectors of disks and floppy disks batch files– *.bat drivers – *. sys libraries – *. dll documents with macros – *.doc, *.xls, *.mdb Web pages with program scripts – *. exe, *. com boot sectors of disks and floppy disks batch files – *.bat drivers – *. sys libraries – *. dll documents with macros – *.doc, *.xls, *.mdb Web pages with scripts do not infect text – *.txt pictures – *.gif, *.jpg, *.png, *.tif sound (*. wav, *.mp3, *.wma) video (*.avi, *.mpg, *.wmv) any data (without program code) text – *.txt pictures – *.gif, *.jpg, *.png, *.tif sound (*.wav, *.mp3, *.wma) video (*.avi, *.mpg, *.wmv) any data (without program code) In order for the virus to perform some actions, it must end up in memory in the form of program code and receive control.


    5 Methods of infection: run an infected file; boot your computer from an infected floppy disk or disk; when autorunning a CD (DVD) disk or flash disk; open an infected document with macros (Word or Excel); open a message with a virus; open a web page with a virus; Allow active content to be installed on a Web page.


    6 Classic file viruses – infect *.exe, *.sys, *.dll files (rarely – embedded in program texts). Boot (boot, from the English boot - loading) - infect the boot sectors of disks and floppy disks, upon loading they immediately end up in memory and receive control. Polymorphic – with each new infection they change their code slightly. Macro viruses – infect documents with macros (*.doc, *.xls, *.mdb). Script viruses – a script (a program in Visual Basic Script, JavaScript, BAT, PHP) infects command files (*.bat), other scripts and Web pages(*.htm, *.html).


    7 Network viruses Mail worms - spread through email as an attachment to a letter or a link to a virus on the Internet; send themselves to all detected addresses Network worms - penetrate the computer through “holes” in the system, can copy themselves into folders open for writing (scanning - searching for vulnerable computers on the network) IRC worms, IM worms - spread through IRC chats and Internet messengers (ICQ, AOL, Windows Messenger, MSN Messenger) P2P worms – spread through file-sharing networks P2P (peer-to-peer) spread through computer networks, use “holes” – errors in Windows protection, Internet Explorer, Outlook, etc. Most active - more than 90%! !


    8 Backdoor Trojans – programs remote administration theft of passwords (Internet access, mailboxes, to payment systems) spies (text entered from the keyboard, screenshots, list of programs, computer characteristics, industrial espionage) DOS attacks (Denial Of Service - denial of service) - massive attacks on sites by command, the server cannot cope with proxy server load – used for mass mailing advertising (spam) downloaders - after infection they download others to the computer malware allow you to gain control remote computer, spread through computer networks, often when installing other programs (infected installers)


    9 Antivirus scanners can find and treat known viruses in memory and on disk; use virus databases; daily database updates via the Internet. they treat viruses known to them cannot prevent infection most often they cannot detect and cure an unknown virus


    10 Anti-virus monitors are constantly in memory in an active state; continuous monitoring; block the virus at the time of infection; can fight unknown viruses; slow down the computer in case of an error; the OS may fail; intercept actions characteristic of viruses and block them (formatting the disk, replacing system files); block attacks via the Internet; check files launched and loaded into memory (for example, Word documents); check email messages; check web pages; checking ICQ messages


    Computer myths Any virus can kill a computer 18% Viruses can spread with any files 65% Viruses can infect emails 100% A computer becomes infected when at least one copy of a virus appears in it 74% The presence of any anti-virus programs on the computer is guaranteed protection against viruses 35%



    At the end of the 60s, the first programs - viruses - appeared on the computers of research centers in the United States. 70s – “classical” viruses – programs capable of reproducing. Early 80s – hundreds of active viruses End of 80s – first epidemics of computer viruses


    The twenty most common malware 1.I-Worm.Klez 2.I-Worm.Sobig 3.I-Worm.Lentin 4.I-Worm.Avron 5.Macro.Word97. Thus 6.I-Worm.Thanatos 7.Macro.Word97. Marker 8.Worm.Win32. Opasoft 9.Worm.Hybris 10.Win95. CIH 11.Worm.Win32. Randon 12.VBS.Redlof 13.Backdoor.Death 14.Win95. Spaces 15.I-Worm.Roron 16.Trojan.PSW.Gip 17.Backdoor.NetDevil 18.Win32.HLLP.Hantaner 19.TrojanDropper.Win32. De lf 20.TrojanDropper.Win32. Ya binder






    From history The worldwide epidemic of email virus infection began on May 5, 2000, when tens of millions of computers connected to the global computer network Internet received an email message with the attractive title ILOVEYOU (English: “I love you”). The message contained an attached file that was a virus. After the recipient read this message, the virus infected the computer and began to destroy the file system.


    Who creates viruses? Viruses are written by experienced programmers or students simply out of curiosity or to take revenge on someone or an enterprise that has treated them in an unworthy manner, either for commercial purposes or for the purpose of targeted sabotage. Whatever the author’s goals, the virus may end up on your computer and try to perform the same harmful actions as the one for whom it was created. It should be noted that writing a virus is not such a difficult task, and is quite accessible to a student studying programming. Therefore, more and more new viruses appear in the world every week. And many of them are made in our country.


    19 Antivirus programs AVP = Antiviral Toolkit Pro (– E. Kaspersky DrWeb (– I. Danilov Norton Antivirus(McAfee (NOD32 (Shareware: Free: Avast Home (Antivir Personal (free-av.com)free-av.com AVG Free (free.grisoft.com)free.grisoft.com There are free trial versions! !




    To periodically check your computer, anti-virus scanners are used, which, after launch, check files and RAM for viruses and ensure virus neutralization. Anti-virus guards (monitors) are constantly located in the computer’s RAM and ensure that files are scanned as they are loaded into RAM.




    23 Kaspersky Anti-Virus File anti-virus (scans files as they are accessed) Mail anti-virus (scans incoming and outgoing messages) Web anti-virus (Internet, scans Web pages) Proactive protection (attempts to detect unknown malware): monitoring the registry, checking critical files signals about “suspicious” memory accesses Anti-spy (fighting Internet fraud) Anti-hacker (detection of network attacks) Anti-spam (incoming mail filter)










    28 Other types antivirus protection firewalls (firewalls, firewalls) block “unnecessary” calls to the network and requests from the network hardware antiviruses protection against changes to the boot sector prohibition of executing code from the data area hardware firewall ZyWALL UTM (ZyXEL and Kaspersky Lab) online (on-line) antiviruses install an ActiveX module on the computer that checks files... or the file is sent to the antivirus developer’s website, most often they do not know how to treat, suggests buying an antivirus doctor


    29 Prevention to do backups important data on CDs and DVDs (once a month? a week?) use an anti-virus monitor, especially when working on the Internet, when working on the Internet, turn on the firewall - this program prohibits exchange through certain communication channels that use viruses to scan using antivirus doctor, all new programs and files, floppy disks, do not open messages from unknown addresses, especially application files, have a boot disk with antivirus


    30 If your computer is infected... Disconnect your computer from the network. Launch antivirus. If it doesn’t help, then... turn off the computer and boot it from boot disk(floppy disks, CDs, DVDs). Launch antivirus. If it doesn’t help, then... remove Windows and install it again. If it doesn’t help, then... format the hard drive (format.com). If this cannot be done, then the disk partition table may be corrupted. Then... create a new partition table (fdisk.exe). If it doesn’t work (the hard drive is not detected), then... you can take the computer for repair.


    Conclusion In conclusion, I would like to warn against being too zealous in the fight against computer viruses. Daily launch of complete scanning hard checking the disk for viruses is also not a brilliant step in preventing infections. The only civilized way to protect against viruses is to take preventive precautions when working on a computer. Often the main problem of the Internet is not viruses and hackers, but such a common phenomenon as computer illiteracy. To use Kaspersky's analogy, ignorance of traffic rules. People who have recently learned to receive and send mail demonize computer viruses, almost imagining them in the form of invisible black worms crawling along wires.


    Here are a few simple rules that you can follow to try to avoid getting infected with viruses. First: they are not afraid of computer viruses, they are all curable. Second: translate Microsoft Outlook into a mode of operation in a zone of limited nodes, which will prohibit it from automatically executing certain programs - the basic principle of the propagation of computer viruses. Third: do not open letters from suspicious recipients. Fourth: use a fresh antivirus.


    Can any virus kill a computer? Can viruses spread with any files? Can viruses infect emails? Does a computer become infected when at least one copy of the virus appears in it? Is the presence of any anti-virus programs on your computer guaranteed protection against viruses? When did the first computer viruses appear? What functions did the first computer viruses perform? What functions can a computer virus perform? Where can I find a list of all computer viruses known to science? What groups of computer viruses exist, how are they characterized, and how to fight them?


    Homework: § questions: 1. What consequences can infection with computer viruses lead to? 2. Why can even a clean formatted floppy disk become a source of virus infection?

    Computer virus

    6. OS hangs.

    Classification of viruses

    I. By method of infection :

    Resident

    Non-resident

    .

    1. Viruses are companions.

    3. Worms.

    For example, an email virus Melissa

    4. Viruses like " Trojan horse » ( BackDoor-G).

    Armageddon, BackOrifice And NetBus

    5. Macro viruses.

    6. Viruses, ".

    CIH or " Chernobyl"

    A virus has appeared in Israel Worm.ExploreZip Melissa with destructive force" Chernobyl

    Antivirus programs

    · scanners;

    · doctoral programs;

    · auditors;

    · filters;

    · immunizers.

    Scanners

    Programs – Doctors

    :

    Auditors

    Filters

    formatting the disk;

    Programs

    What harm do viruses cause?

    Various viruses perform various destructive actions:

    Displays annoying text messages on the screen;

    Create sound effects;

    Create video effects;

    Slow down the computer, gradually reduce the amount of RAM;

    Increase equipment wear;

    Cause failure of individual devices, freezing or rebooting of the computer and the collapse of the entire computer;

    Simulate repeated operating system errors;

    Destroy the FAT table, format it HDD, erase BIOS, erase or change settings in CMOS, erase sectors on a disk, destroy or distort data, erase anti-virus programs;

    Carry out scientific, technical, industrial and financial espionage;

    They disable information security systems and give attackers secret access to computer;

    They make illegal deductions from every financial transaction, etc.;

    The main danger of self-replicating codes is that virus programs begin to live their own lives, practically independent of the program developer. Just like in a chain reaction in a nuclear reactor, once the process is started it is difficult to stop.

    What viruses are there?

    Let's consider main types of viruses. There are a large number of different classifications of viruses:

    by habitat:

    - network viruses distributed by various computer networks;

    - file- infect executable files with the extension exe and com. This class also includes macroviruses written using macro commands. They infect non-executable files (in Word, Excel);

    - boot- are being implemented into boot sector disk or sector containing the boot program system disk. Some viruses write to free sectors of the disk, marking them in the FAT table as bad;

    - boot-file- integrate the features of the last two groups;

    · according to the method of infection (activation):

    - resident The virus can be logically divided into two parts - installer And resident module. When an infected program is launched, control is gained by the installer, which performs the following actions:

    1. places the resident virus module in RAM and performs the operations necessary to ensure that the latter is stored there permanently;

    2. replaces some interrupt handlers so that the resident module can receive control when certain events occur.

    - non-resident viruses do not infect RAM and are active only once when an infected program is launched;

    · according to the degree of danger:

    - not dangerous- sound and video effects;

    - dangerous- destroy some files on the disk;

    - very dangerous- format the hard drive yourself;

    · according to the features of the algorithm:

    - companion viruses do not change files. The algorithm of their work is that they create new satellite files (duplicates) for exe files, having the same name, but with the extension com. (com file is detected first, and then the virus launches the exe file);

    - worms (replicators)- similarly to companions, they do not change files and disk sectors. They penetrate the computer via the network, calculate network addresses other computers and send their copies to these addresses. Worms reduce network bandwidth and slow down servers;

    - invisible (stealth)- use a set of tools to disguise their presence on a computer. They are difficult to detect because... they intercept OS calls to infected files or sectors and substitute uninfected sections of files;

    - polymorphics (ghosts, mutants)- encrypt their own body different ways. They are difficult to detect because... their copies practically do not contain completely matching sections of code;

    - Trojan horse- disguises itself as a useful or interesting program, while also performing destructive work during its operation or collecting information on the computer that is not subject to disclosure. Unlike viruses, Trojans do not have the property of self-reproduction.

    by integrity:

    - monolithic- the program represents a single block;

    - distributed- the program is divided into parts. These parts contain instructions that indicate how to put them together to recreate the virus.

    Lecture 4. Computer viruses and antivirus tools

    Computer virus is a program capable of creating copies of itself (not necessarily completely identical to the original), introducing them into various objects of systems and networks and performing certain actions without the user’s knowledge.

    A program that has a virus inside it is called infected or infected. When an infected program starts running, the virus first takes control. The virus infects other programs and carries out planned actions. After that, it transfers control to the program in which it is located. On average, about 300 new varieties of viruses appear per month.

    Symptoms of a computer virus infection:

    1. Slowdown of some programs.

    2. Increase in file sizes, especially executable ones.

    3. Random appearance of previously non-existent files.

    4. Reducing the amount of available OP compared to the normal operating mode.

    5. Sudden video and sound effects.

    6. OS hangs.

    7. Writing to disk at an unexpected time.

    8. Termination of previously normally functioning programs.

    Classification of viruses

    I. By method of infection :

    Viruses are divided into resident and non-resident

    Resident– they leave their resident part in the operating system, which then intercepts calls from uninfected programs to the OS and injects itself into them.

    Non-resident– do not infect the OS, they are active only once when the infected program is launched.

    II. According to the features of the algorithm.

    1. Viruses are companions.

    For files with the EXE extension, they create new infected files with the same name, but with the COM extension. When starting programs, the OS first launches files with the COM extension, then those with the EXE extension. As a result, the infected file will be launched first and infect other programs.

    Change the contents of disk sectors or files. This group includes all viruses that are not companions or worms.

    3. Worms.

    These are viruses that spread on the network, penetrate memory, find network addresses and send copies of themselves to these addresses. Worms reduce network bandwidth and slow down servers.

    For example, an email virus Melissa caused massive disruptions to postal services in many countries. This virus disguises itself as an email message and, when opened by a user, sends similar messages to the first 50 addresses in their address book.

    4. Viruses like " Trojan horse» ( BackDoor-G).

    Disguised as useful program. They perform destructive work, for example, erasing the FAT table.

    Similar viruses are Armageddon, BackOrifice And NetBus, they are characterized by the fact that they are a mixture of viruses and means of hacking the protection of computer programs.

    5. Macro viruses.

    Use the capabilities of macro languages ​​built into text editors and spreadsheets.

    6. Viruses, destroying computer hardware”.

    CIH or " Chernobyl", triggered on April 26 (the anniversary of the Chernobyl disaster). Another version of the virus manifests its destructive properties on the 26th of every month. Written by a programmer in Taiwan, Chernobyl corrupts the data on the hard drive and destroys the Basic Input/Output System (BIOS), making it impossible to boot the computer, ultimately requiring the ROM chip to be replaced. The carrier of the virus is a CD-ROM with pirated software.

    A virus has appeared in Israel Worm.ExploreZip, combining the fertility of the "worm" Melissa with destructive force" Chernobyl" This virus also spreads by email, but it comes in response to real messages, so it does not cause any particular suspicion in the user. The viral message contains files packed with a ZIP archiver program. When you try to unzip, the virus displays an error message and infects the computer, after which it erases all data from the hard drive.

    Antivirus programs

    These programs can detect only those viruses whose signatures (portraits) are known to them - placed in the program library.

    Antivirus programs are divided into:

    · scanners;

    · doctoral programs;

    · auditors;

    · filters;

    · immunizers.

    Scanners scan OP, disks, searching for infected files.

    Programs – Doctors not only find infected files, but also treat them by removing the body of the program - the virus - from the file.

    The most famous programs are Doctors:

    Auditors– programs that analyze the current state of files and system areas of the disk, and also compare it with information previously saved in one of the auditor files. In this case, the status of the FAT table, file length, creation time, attributes, and checksums are checked.

    Filters– these are resident programs (watchmen) that notify the user of all attempts by any program to perform suspicious actions. Filters control:

    · update program files and system area of ​​the disk;

    formatting the disk;

    · resident placement of programs in the OP.

    Programs– filters must be installed when working on the Internet.

    1. Before reading from storage media, check the media for viruses.

    2. Scan files immediately after unzipping.

    3. Do not leave media in the slots when turning on and rebooting the PC, because this may lead to boot viruses.

    4. Having received an email with an attached executable file, do not run this file without first checking it.

    5. When installing a large software product check all distribution files, and after installation, check for viruses again.

    6. Update anti-virus program databases.

    : to familiarize students with the concept of a virus, an anti-virus program, types of viruses, modern anti-viruses, and methods of fighting viruses.

  • Developmental:
    • develop the ability to defend one’s point of view in a discussion, computer literacy, and cognitive activity.
  • Educational:
    •  cultivate attention, accuracy, and thrifty attitude towards software and PCs.

    Equipment:

    • Computer class
    • Projector
    • Software: electronic lecture ( Annex 1), Microsoft Power Point, Microsoft Excel, Microsoft Security, Avast programs
    • Flash card infected with a virus
    • Tokens with numbers

    Literature:

    • N.D. Ugrinovich Informatics. Basic course 7th grade. Moscow, BINOM, 2005
    • www.metod-kopilka.ru (presentation by teacher Zhuravlev A.A. MBOU Secondary School No. 3, Donetsk)
    • http://ru.wikipedia.org/
    • http://www.ctspi.ru/
    • http://informatika.sch880.ru/
    • http://www.leon4ik.com (cartoon)
    • Verbal (lecture, conversation-discussion).
    • Visual (electronic presentation, review of antiviruses).
    • Game (questioning students on the topic)

    During the classes

    1. Organizational moment

    2. Introduction of new material (electronic presentation is used).

    1. Historical information

    The first infection with the virus occurred in 1986 in the USA. A virus called “Brain” infected floppy disks, created by Pakistani programmer Alvi. In the USA alone, this virus infected over 18 thousand PCs.

    When they began to develop viruses, they were only of a research nature, but gradually this turned into a hostile attitude towards users.

    2. What are computer viruses?

    Computer viruses are a well-written program that can reproduce, copy itself without permission, spontaneously attach itself to other programs, and, unnoticed by users, embed its code into files, documents, Internet Web pages, and email messages.

    3. Signs of viruses

    1. Stopping or malfunctioning programs that were previously functioning.
    2. Slow PC
    3. Inability to boot OS
    4. Disappearance of files and folders or distortion of their contents.

    4. Why is a computer virus dangerous?

    After infecting a PC, the virus can become active (or wake up) and begin its malicious actions.

    Activation of the virus may be associated with some events; (For example):

    • Coming of a certain date
    • Starting the program
    • Opening a document

    5. Types of computer viruses

    Computer viruses are classified according to their habitat and degree of impact.

    By “degree of impact”

    • Non-hazardous
    – as a rule, these viruses clog the computer’s memory by reproducing and can perform minor mischief – play a melody embedded in them or show a picture;
  • Dangerous
    • – these viruses can create some disruptions in the functioning of the PC – crashes, reboots, PC freezes, slow computer operation, etc.;
  • Very dangerous
    • – dangerous viruses can destroy programs, erase important data, kill boot and system areas of the hard drive, which can then be thrown away.

    Computer viruses by "habitat"

    • File viruses –
     are implemented into programs and are activated when they are launched. Once launched, an infected program can infect other files until the computer is turned off or the operating system is restarted. .
  • Macro viruses –
    •  infection occurs when a document file is opened in a program window, unless the ability to execute macro commands (macros) is disabled in the program.
  • Network viruses –
    •  can transmit their program code over computer networks and run it on computers connected to this network.

    or when “traveling” on the World Wide Web.

    6. You need to know this

    If, when you go to a website, you receive a message that your computer is infected by one or more antiviruses, do not rush to agree to the proposed scan of your computer and installation of a free program for this purpose. Nowadays, so-called rogueware, false antivirus software, has become widespread, the purpose of which is to force the user to pay money for a paid version of supposedly high-quality antivirus software. If you agree to this setting, the program running on your computer will continue to “block and destroy” viruses, showing its “quality”. In reality, the program does nothing, but simply displays windows about detected viruses and offers to buy a paid version. According to Symantec, there are already tens of millions of computers in the United States on which more than 250 varieties of such rogue antivirus programs are installed.

    7. Dangerous viruses

    The spread of computer viruses (discussed on slide 11).

    8. A worldwide email virus epidemic has begun. May 5, 2000, when tens of millions of computers connected to the Internet received an email message with an attractive title I LOVE YOU. The message contained an attached file that was a virus. After the recipient read this message, the virus infected the computer and began to destroy the file system.

    9. How to protect yourself from viruses?

    For the purpose of preventive protection against computer viruses, it is not recommended to run programs, open documents and email messages received from dubious sources and not previously scanned by anti-virus programs.

    Infection with a network virus can occur when working with e-mail or while “traveling” on the World Wide Web.

    Antivirus programs are the most effective in fighting computer viruses. Antivirus programs use constantly updated lists of known viruses, which include the name of the virus and its program code.

    If an anti-virus program detects a virus program code in any file, the file is considered infected with a virus and is subject to “treatment”, that is, the virus program code is removed from it.

    If treatment is impossible, the entire file is deleted

    11. The process of virus infection and file disinfection. (discussed on slides 16-17)

    12. Antivirus programs

    • Antivirus scanners
    , which, after launch, check files and RAM for viruses and ensure their neutralization.
  • Antivirus "watchmen"
    •  (monitors 10. Antivirus programs

    The most effective antivirus programs in the fight against computer viruses are:

    • Kaspersky Lab Antivirus
    • Doctor Web
    • NOD 32
    • AVAST
    • Microsoft Security
    • Avira

    13. The most popular viruses last week. (slide 20) (Before the lesson, this data must be updated.)

    3. Conversation-discussion with students

    1. Who do you think creates computer viruses and why?
    2. What is better: a downloaded antivirus on the Internet or a licensed antivirus?

    (Each student must put forward his own hypothesis and defend his point of view)

    ) are constantly located in the computer’s RAM and ensure that files are checked as they are loaded into RAM.

    5. The conclusion of the lesson is carried out in the form of a game “Save the computer from viruses”

    Students are asked to answer 6 questions. For each correct answer, students receive a token with a number; if no one answers correctly, then the token is not issued. From the received tokens, students must add up a code and enter it into the computer (a sheet has previously been created in Microsoft Excel ( Appendix 2)).

    Questions:

    1. In what year did the first virus infection occur? (token 6)
    2. In what year did mass infection with the virus occur? (token 2)
    3. What was the name of the first computer virus? (token 3)
    4. What is the most effective way to fight viruses? (token 5)
    5. Types of viruses (token 1)
    6. Types of antiviruses (token 4)

    Homework

    clause 1.7, notes in notebooks

    At the end of the lesson, students are invited to watch the cartoon The Thunderstorm (episode 24) from the Pochemuchka series.



    Tests for comparative testing of shockers "on the knee"