Computer Viruses


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Some basic information about the history, evolution and prevention of viruses. NOTE: This is my updated version from 2009.

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Computer Viruses

  1. 1. Computer VirusesPresented by: Marcus Guidry, A+, Net+, Sec+, MCPNetwork Analyst / Help Desk EngineerRegion 7 Officer – AITP Student Leadership Council
  2. 2. Table Of Contents• Introduction – What is a Virus?• History of the Virus• Variants and Forms of Malware• How to Defend Yourself
  3. 3. Intro – What is a Computer Virus?• A computer virus is a small software program that spreads from one computer to another computer and that interferes with computer operation.• A computer virus may corrupt or delete data on a computer, use an e-mail program to spread the virus to other computers, or even delete everything on the hard disk.
  4. 4. Some Examples of Viruses• Melissa – considered the first email virus; released in 1999• ILOVEU – sent passwords back over the network and infected machines; written by a Filipino student in 2000.• Boot Sector – spread by floppy disks in the 80s and 90s• Klez – used emails and email address books to replicate and spread; released in 2001
  5. 5. History of the Virus• First Virus Created? – The Brain Virus• The Brain Virus was: • created in 1986 by two Pakistani brothers, Amjad and Basit Farooq Alvi. • Was spread around by floppy disks • Infected boot records only (not the HDD) • Cluttered free space on a floppy making it unusable.
  6. 6. How The Brain Virus Was Spread• According to a 1988 article in Time Magazine, a shop called “Brain Computer Services was selling brand-name computer programs, such as Lotus 1-2-3 and WordStar ... for as little as $1.50 each.” From 1986-87, many Americans stopped by their store, purchased these disks, and brought them back home..
  7. 7. More On “The Brain” Virus• As Americans loaded these boot-legs programs from their floppy disk to their computers, “a snippet of computer code many consider to be the worlds most sophisticated computer virus“ was spread rapidly and infected over 100,000 disks.• Source: Time Magazine (1988) By Philip Elmer- DeWitt and Ross H. Munro/Lahore Monday, Sep. 26, 1988 “You Must Be Punished”
  8. 8. More About the “Melissa” Virus• Written by David L. Smith in March 1999• It infected countless thousands of PCs (estimated damage = $80 million).• Replicated by sending copies of itself to addresses in the Microsoft Outlook address book.• Forced companies like Microsoft, Intel, and Lockheed Martin to shut down their email servers.• The author is subsequently jailed for 20 months.
  9. 9. Many Variants of Malware• Worms – malicious software programs designed to replicate themselves, find open ports on your computer, and bottleneck your computer.• Trojan Horse – malicious software that is disguised as another application but causes harm to your computer. It hides itself and then add a backdoor which can be opened later to run denial of service (DoS) attacks.• AdWare – spy programs installed that allows companies to track your activities on visited websites (usually without your consent).
  10. 10. Variants of Malware (Cont’d)• Rootkits – malicious programs that are installed below the operating system (OS) level. These programs usually load up during the boot process (the kernel or “root” level), just before the OS is fully loaded.• The “kits” part refers to the different tools hackers can use to maintain secret access to your machine once the rootkit is installed. • NOTE: Not all rootkits are detectable by antivirus or anti-rootkit programs. If you discover a rootkit on your machine, experts recommend reinstalling the OS!!
  11. 11. The First Worm? • Morris Worm • Written by Cornell student Robert Tappan Morris in 1988 • Activated the worm from a computer at MIT • Found vulnerabilities in Unix and corrupted thousands of computers the first day released • Convicted under the 1986 Computer Fraud and Abuse Act, sentenced to community service • Present role: Professor at MIT
  12. 12. Some Well-Known Worms• Nimda - infected machines via email, web, IIS, network shares and backdoors; released in 2001• MyDoom – massive email worm (created 2004)• SoBig – email worm (variants A – F)• Code Red and Code Red II – infected thousands of Windows NT/2000 servers, over $2 billion in damages• SQL Slammer – shut down Microsoft’s Outlook and stopped databases nationwide (Bank of America to name one) in 2003• Blaster Worm – a worm that generated buffer overflow attacks, causing havoc in 2003.
  13. 13. Are Viruses and Worms the Same?• Viruses are dependent on other programs to help them spread. They “piggyback” off existing programs and then execute when opened by a user.• Worms can replicate themselves and do not need to “piggyback” in order to execute.
  14. 14. The Trojan HorseImage of theTrojan Horse usedin the movie“Troy” in 2004
  15. 15. The First Trojan Horse?• PC-Write Trojan. According to Kylee Dickey of Smart Computing Magazine, the first Trojan horse, PC-Write Trojan, appeared back in 1986.• It pretended to be version 2.72 of the shareware word processor, PC-Write. (Quicksoft, the company that made PC-Write, never released a version 2.72.)• It performed two actions: 1. It wiped out the FAT (file allocation table; system a PC uses to organize contents on the hard drive) 2. It formatted the hard drive, deleting all saved data.
  16. 16. Some Other Well Known Trojans• BackOfrice• NetBus• Sub Seven• Liberty Trojan – In 2000, people thought that this program was a patch that allowed PDA users to play Nintendo Game Boy games on the Palm OS. Instead, it deleted personal files when opened.• Storm – This nasty 2006 Trojan program infected millions, allowing hackers to turn infected machines into bots.
  17. 17. Adware and Rootkits• Adware and rootkits can also cause major problems for computer users in different ways!!
  18. 18. AdWare Is A Big Problem• Every day, thousands of advertisers track you on every website you visit (via cookies and other tools) and collect your personal data without your knowledge.• Examples of Companies Tracking You: • Google Analytics • Omniture • AddThis • Quantcast
  19. 19. The First Rootkits?• SunOS rootkit by Lane Davis and Steven Dake in 1990• NTRootkit created by Greg Hoglund in 1999• Sony BMG’s Extended Rights Protection in 2005 – rootkit from CDs that limited users’ ability to access their music CDs• Mebromi – considered the first BIOS rootkit in the wild
  20. 20. Dealing With Rootkits• Here are some recommended anti-rootkit tools: • RootkitRevealer • Kaspersky TDSS Killer • GMER • Hitman Pro • VICE • Rkhunter (Linux based) • Unhide and unhide.rb (Linux based)• Recommended Rootkit Removal Guide: • See Computer Weekly’s Rootkit and Malware Guide: malware-detection-and-removal-guide• Again, if the rootkit can’t be completely removed, reinstall your OS
  21. 21. How to Defend Yourself?• Use A Firewall – There are two types: 1. Hardware – some examples are: • Cisco PIX • CheckPoint 2. Software – some examples are: • Comodo • Zone Alarm • Windows Firewall
  22. 22. Using Antivirus Software• Use Antivirus Software to protect your computer. • According to Microsoft, less than 30 percent of all users have up-to-date software on their machines (including security patches). • Some Recommended Antivirus Programs • AVG (by Grisoft) • Bitdefender • Avira • Norton • McAfee • TrendMicro
  23. 23. Use AntiSpyware Programs!• Spyware is usually hidden in cookies and in the Windows registry. Some are dangerous and can hinder performance. Protect your OS against spyware.• Some popular AntiSpyware Programs: • Windows Defender • Ad-Aware • Spybot Search & Destroy • Spyware Blaster
  24. 24. Use Ad Blockers!!• Take control of your privacy. You can stop ad networks from snooping on you.• Here are some adware blockers that are highly recommended. • DoNotTrackPlus by Abine • Adware Blocker • Ghostery• Most web browsers also have a built-in anti- phishing tool that should be turned on.
  25. 25. Other Virus Prevention Tips• Educate Yourselves!! – This sounds simple, but nothing is more important than educating people on the fundamentals of computer malware prevention!• Update patches for third-party Applications • Third party apps like Adobe must be updated regularly to stop newly discovered exploits• Update patches for the OS (MS and Linux) • Microsoft Security Updates (available on Patch Tuesday – second Tuesday each month)
  26. 26. Questions or Comments?