Computer virus


Published on

  • Be the first to comment

  • Be the first to like this

No Downloads
Total views
On SlideShare
From Embeds
Number of Embeds
Embeds 0
No embeds

No notes for slide

Computer virus

  1. 1. Importance of computer Computer crime computer virus BY
  2. 2. Importance of computer in different fields• what are computers?• Some say that they are simple electronic devices that accept inputs, process data and produce outputs. Computers may be simple but they can be very powerful. Computers have begun to meet the barrier imposed by the speed of light in achieving higher speeds.
  3. 3. Importance of computer in different fields• Education• Science• Communications• Business• Government• etc
  4. 4. Importance of computer in different fields• Science All branches of science, from astronomy to zoology, depend on computers to further their knowledge on increasing the life span of man. The MRI, the PET, and other computer-aided machines help doctors and scientists to better understand the people’s medical needs.
  5. 5. Importance of computer in different fields• Communications Do you know that computers have even transformed how you communicate with each other through the advancements in technology? One of these advancements is the Internet. Who among us does not know anything about the Internet? Perhaps, using computers will never be complete without using the Internet. This global network of networks have swept the lives of many people as daily tasks become handier, communications more convenient, and most of all, sources of information broader and more accessible.
  6. 6. Importance of computer in different fields• Business Computer has changed how we do business. Gone are the days of labor-intensive and manual way of inputting data through ink and paper. Now, with a few taps of keys and a few clicks of the mouse, good and productive business is on its way.
  7. 7. Importance of computer in different fields• Government Government offices also depend on computers for its basic needs. From simple letters to the more complicated projects are now being produced through the use of computers. Government agencies and their databases are now interlinked, making it easier for the agencies to monitor economic developments.
  8. 8. Computer Crime
  9. 9. Computer Crime• Software Piracy• Protections from Piracy
  10. 10. Computer Crime - Software Piracy• Software piracy – the illegal copying of software programs – is the biggest legal issue affecting the computer industry.• Piracy is of greatest concern to developers of commercial software, or programs that must be purchased before using.• Piracy is less of a concern for shareware makers, whose programs must be registered but not always purchased.• Piracy is not a concern for freeware, which is software that can be freely distributed by anyone.
  11. 11. Computer Crime - Protections from PiracyVarious forms of copy protection have been used to discouragepiracy, including:• Installation diskettes that record the number of times the software is installed.• Hardware locks, without which the program cannot function.• Passwords, serial numbers, or other codes required for installation.
  12. 12. Theft - Hardware and Software Theft• As PCs become smaller – and as more people use laptop and handheld computers – hardware theft is becoming a growing problem.• Software theft is also a major problem for companies, many of which must purchase large quantities of expensive software programs.• To combat hardware and software theft, many companies are locking hardware to desks and securing software in libraries, granting access to employees only as needed.
  13. 13. computer virus
  14. 14. Computer VirusesA virus is a parasitic program that infects another program (thehost). Most viruses fall into the following categories:Categories of VirusesBoot sector viruses Self-encrypting virusesCluster viruses Self-changing virusesFile-infecting viruses Stealth virusesWorms Macro virusesBombs Joke programsTrojan Horses Bimodal virusesPolymorphic viruses Bipartite virusesSelf-garbling viruses Multipartite virusesE-mail viruses Macro viruses
  15. 15. Types of Viruses• Trojan Horses – appears as interesting program file but when installed it allows intruders to access and read your files• Worms – virus that copies and multiplies itself by using computer networks and security flaws• E-mail Viruses – use e-mail messages to spread which allow it to automatically forward itself to thousands of people
  16. 16. Types of Viruses• Boot Sector Virus – Infects the boot or MBR of diskettes and hard drives through the sharing of infected disks and pirated software applications – Once your hard drive is infected all diskettes that you use in your computer will be infected• Program Virus – Becomes active when the program file (usually with extensions .BIN, .COM, .EXE, .OVL, .DRV) carrying the virus is opened – It then makes copies of itself and will infect other programs on the computer• Multipartite Virus – Hybrid of a Boot Sector and Program viruses – It infects program files and when the infected program is active it will affect the boot record
  17. 17. Types of Viruses• Stealth Virus – Disguises itself to prevent from being detected by antivirus software – It alters its file size or conceals itself in memory• Polymorphic Virus – Act like a chameleon, changing its virus signature (binary pattern) every time it multiples and infects a new file• Macro Virus – Programmed as a macro embedded in a document, usually found in Microsoft Word and Excel – Once it gets in to your computer, every document you produce will become infected – Relatively new type of virus and may slip by your antivirus software if you dont have the most recent version installed
  18. 18. Computer Viruses - Preventing InfectionViruses are spread in several ways. The most common are:• Receiving an infected disk.• Downloading an infected executable file from a network or the Internet.• Copying a document file that is infected with a macro virus.To avoid viruses, you should:• Treat all disks as though they are infected.• Install an antivirus program and keep its virus definitions (database of virus information) up to date.• Run your antivirus program regularly.