Virus worm trojan


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Virus worm trojan

  1. 1. iruses orms rojans& and Other Info-Tech Diseas by: Rafeth Ahmed Nitish Baghla
  2. 2. table of content1. Computer abuse 4. Trojan horses, worms a) What is computer abuse… a) Worms b) Trojan Horses2. Spam a) What is spam? 5. Summary and conclusions b) How does spam work? c) How’d they get my email? 6. References d) Spam prevention3. Viruses a) Computer Viruses b) History of viruses c) History of virus continued… d) Types of viruses e) Virus effects… f) Virus process and cycle g) Top 10 virus attacks and cost h) Virus prevention i) Why do we have viruses?
  3. 3. Is This Computerabuse? 1 or is it more like this? 2
  4. 4. abuse…"The unauthorized use of, or access to, a computer forpurposes contrary to the wishes of the owner of the computeror the data held thereon.” 3Such as:  Hacking  Pornography  Viruses
  5. 5. spam ? no… …not… … this kind 4
  6. 6. ? Spam is all those unwanted advertisement of a company or their products distributed online. Most spams are delivered via emails. To avoid being spammed companies do have filters, but the best we can do is just ignore the emails and delete them. 5
  7. 7. how doesspam work ? Filter BypassPaid E-mail Junk Mail Humans Spam Spam Phishing Commercial Advertising
  8. 8. how’d they getmy e-mail ? 6 7 8 9
  9. 9. spam prevention Don’t give out email addresses to unreliable sourcesSpam protection in your computer (most email servicesprovide spam filtering)Read carefully when filling out online forms requesting youre-mail address, and exercise your choice.Use multiple e-mail addresses.Short e-mail addresses are easy to guess, and may receivemore spam.Spam protection from your ISP
  10. 10. 12 1110
  11. 11. computer virus To be defined as a virus, a Virus Components: program must: The Replication mechanism Replicate itself in order to  allows virus to copy itself carry out a mission. Create damage to the The Protection mechanism computer system "infected".  Hides virus from detection The Trigger Or A virus is a program which  Mechanism which will set off reproduces itself, hides in the payload other computer code without permission and does nasty or The Payload undesirable things, not  Effect of the virus intended by its victim. 13
  12. 12. viruses… Technically, the concept of a  The first virus “in the wild,” computer virus was first as they say, infected Apple imagined in 1949, well II floppy disk in 1981. Its before computers became name was” Elk Cloner”. all it commonplace. did was display a short Von Neumann used his rhyme onscreen: theories in the 1950s, at Bell Labs. “It will get on all your disks It will infiltrate your chips Yes it’s Cloner! It will stick to you like glue It will modify ram too Send in the Cloner!” 14
  13. 13. viruses continued… in 1983 when Fred Cohen, demonstrates a computer virus during a security seminar at Lehigh University in Pennsylvania. In 1986, the Brain virus became the first documented file infector virus for MS-DOS computers 15
  14. 14. types of virusesBoot Viruses Infect the boot block on a floppy or hard diskFile Viruses Infect .EXE or .COM filesMulti-partite Viruses Infect both boot blocks and executable files.Polymorphic Viruses Is self-modifying, changes each time it infects a file or disk.Meta Viruses First viruses to infect data files and to work on multiple platforms. 13
  15. 15. virus effects… Trivial, simply reproduces or displays messages. Minor, alters or deletes infected files. Moderate, wipes out entire disk drive. Major, slowly corrupts data with pattern, making restoration difficult. Severe, slowly corrupts data without pattern, making restoration impossible. Unlimited, virus which discovers system administrators password and mails it to one or more users, tempting them to use it for illegal purposes 13
  16. 16. and cycle Virus Process 16Virus Cycle 16
  17. 17. top 10 virusattacks and cost…Rate Name Year Cost ($ Million)1 Morris 1998 10 – 1002 Melissa 1999 60 – 1003 Love Letter 2000 5.54 Code Red 2001 2.65 Nimda 2001 6356 SQL Slammer 2003 750 – 10007 MS Blaster 2003 100 – 1508 MyDoom 2004 2509 Sasser 2004 12010 Witty 2004 10 – 30 17
  18. 18. prevention …There are plenty of companiesdedicated in preventing virusesfrom infecting our computers.They are known as antiviruses orcomputer security systems 19 Such as… 18 20
  19. 19. why do we haveviruses? Why are there so many new viruses? Is it because some troll is making it for fun? Or is it… Because antivirus companies are creating new ones so we are bound 21 to buy their products?
  20. 20. worms 22 no… 23 …not… … these kinds ?
  21. 21. worms A worm is a program that scans a company’s network, or the Internet, for another computer that has a specific security hole. It copies itself to the new machine (through the security hole), Understanding Computer Viruses then starts replicating itself there. Worms replicate themselves very quickly; a network infected with a worm can be brought to its knees within a matter of hours. Worms don’t even have to be delivered via conventional programs; so-called “fileless” worms are recent additions to the virus scene. While in operation, these programs exist only in system memory, making them harder to identify than conventional file-hosted worms. 16
  22. 22. trojan horse A Trojan horse is a program that claims to do one thing but then does something totally different. A typical Trojan horse has a filename that makes you think it’s a harmless type of file; it looks innocuous enough to be safe to open. But when you run the file, it’s actually a virus program that proceeds to inflict its damage on your system. It delivers its payload through deception, just like the fabled Trojan horse of yore. Trojan horses are becoming more common, primarily through the spread of Internet-based e-mail. These e-mail Trojans spread as innocent-looking attachments to e-mail messages; when you click to open the attachment, you launch the virus. 16
  23. 23. conclusion Well most people believe that all computer threats are due to a virus, but now we know that there are a lot of different threats beside viruses Such as there are spams, trojans, worms, From spams we know there are different sorts, such as phishing Back to viruses we learnt a little bit of what it does such as how it infects our computer system and destroys it slowly.
  24. 24. 1.2.3. references amazoncom_launche_wireless_superstore---50226711--images--amazon.com_logo.jpg7. 3199745-computer-virus.jpg13. D4/s1600/norton-360.gif20.
  25. 25. thank you are there any question ? 24