Computer virus-and-antivirus


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Computer virus-and-antivirus

  1. 1. 1Computer security AgainstthreatsA presentation by Vishwaraj Yadavand Saurav Mohapatra of class 11thCannas
  2. 2. 2Contents• Security of computer• Threats to computer security• Solutions to computer threats
  3. 3. Security of system• Nowadays, Computers are usedeverywhere. Various data is sharedfrom one computer to another. Butsometimes the data is not trustworthy,or it behaves in an undesired manner. Ifthis happens then our computer isinsecure.3
  4. 4. Continued….• So to make our computer secured weneed Computer security.• It is the ability of computer to protectinformation & system resources withrespect to confidentiality & integrity.4
  5. 5. • A threat is a potential violation tosecurity. When it is executed it becomesattack.5Threats to computersecurity
  6. 6. 6Threats to computersecurityPCIntrusionSpyware Adware Spamming VirusesWormsTrojansPhishing
  7. 7. 7Computer Virus• Viruses are malicious codes that causedamage to data, they can attack to anypart of computer’s software such as bootblock, files & application programs etc.• Worms & Trojan horses are similarprograms having virus-like effects.
  8. 8. Computer Virus• Worms- A self-replicating programwhich eats up the entire disk space ormemory.• Trojan Horses- It is a program whichappears harmless but performsmalicious functions such as deleting ordamaging files.8
  9. 9. Computer Virus• How do viruses damage computer?1. They damage or delete files.2. Slow down the computer.3. Invade your email program.9
  10. 10. 10ComputerVirusesBoot sectorvirusesFilevirusesMacrovirusesMultipartitevirusesPolymorphic viruses
  11. 11. 11Computer VirusTypes of Computer Virus• Boot Sector VirusBoot sector viruses infect the boot sectors on floppydisks and hard disks, and can also infect the masterboot record on a users hard drive.• File VirusOperate in memory and usually infect executable files.• Polymorphic virusThey mutate their own code to make it difficult forantivirus to detect and remove.
  12. 12. Computer Virus• Multi-partite VirusMulti-partite viruses have characteristicsof both boot sector viruses and fileinfector viruses.• Macro VirusThey infect macro utilities that accompanysuch applications as Microsoft Word,Excel and outlook.12
  13. 13. 13Example of computer virusI LOVE YOU• VBS/LoveLetter is a VBScript worm. Itspreads through e-mail as a chain letter.• This worm sends itself to email addresses inthe Microsoft Outlook address book and alsospreads to Internet chatrooms.• This worm overwrites files on local andremote drives, including files with theextensions .html, .c,.bat,.mp3 etc.
  14. 14. spyware• Spyware is a software which is installedin the computer to spy on the activitiesdone on the computer.• It tracks what all user does and reportsit to the central source. They are usedto spy either for legal purpose or illegalpurpose.14
  15. 15. Spyware15
  16. 16. spyware• How do spyware cause damage?1. They monitor information such as whatsites you visit or record keystrokeswhich can lead to identity thefts.2. Some spywares alter PC settings likeposition of your desktop icons etc.3. It can rob the PC of system speed andinternet access efficiency.16
  17. 17. Adware• These are programs that deliverunwanted ads to computer(in the formof pop-ups).17
  18. 18. Adware• How do adware damage computer?1. Adware tracks the information just likespyware.2. When adware infects the computer, wewill receive frequent pop-upsappearing out of nowhere.3. The appearing of large number of ads,the PC starts to slow down.18
  19. 19. Spamming• Spamming refers to sending of bulk-mail by an identified or unidentifiedsource. The attacker keeps on sendingbulk mail to various accounts until mailserver runs out of disk space.19
  20. 20. Spamming• How do spams damage computer?1. Spam messages circulating acrossinternet disrupt email delivery & systemperformance.2. Spams eats up time.3. Spam messages contain fraud materialand can even spread viruses.20
  21. 21. PC Intrusion• Every PC connected to Internet aretarget of hackers. Hackers constantlyattack computers.21
  22. 22. PC Intrusion• How can it damage the system?1. Sweeper attack- Hackers use it todelete all the data in the system.2. Denial of service- Thais attack eats upall the resources of system and systemor application doesn’t work.3. Password guessing- Hackers crack orguess passwords of account to gainentry into remote computer systems.22
  23. 23. Solutions to computerthreats• The computer security protects thecomputer through threats by takingactions or taking prevention. There aretwo solutions to these threats-1. Active Protection2. Preventive Maesures23
  24. 24. Continued…• Active Protection- Installing and usingantivirus that includes Internet security-which includes protection againstviruses, spyware & PC intrusion.• Preventive measures- Even thoughsecurity programs detect & eliminatethreats but we should help preventthese issues from ever arising.24
  25. 25. Continued…• Solutions to viruses, adware,spyware1. Active protection• Use Anti-virus and Anti-spywaresoftware.• Download updates regularly.• Run frequent full-system scans.25
  26. 26. 2. Preventive measures• Keep your system up-to-date.• Use caution when downloading files onthe internet.• Be careful with email.• Disable Cookies, if possible.26Continued…
  27. 27. • Solutions to Spam1. Active Protection:-Methods used byanti-spam software-(a)Sender FilteringDigital CertificatesDigital Signatures(b)Keyword Filtering27Continued…
  28. 28. Solutions to PC intrusion:-AuthorizationAuthenticationFirewall28Continued…
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