Computer viruses
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This document defines and describes different types of computer viruses. It begins by defining a computer virus as a program that spreads itself by infecting files and disks without the user's knowledge. It then lists and describes 7 common types of viruses: boot sector viruses, multipartite viruses, worm viruses, email viruses, macro viruses, script viruses, and Trojan horses. The document explains how each type infects and spreads. It concludes by emphasizing the importance of prevention through safe computing practices and using virus protection software.
Computer viruses
- 1. Computer Viruses PRANJAL SAIKIA KAZIRANGA UNIVERSITY M.Sc (IT)
- 2. Definition of Virus A computer virus is a program designed to spread itself by first infecting executable files or the system areas of hard disks and then making copies of itself. Viruses usually operate without the knowledge or desire of the computer user
- 3. Types of Computer Virus 1. Boot Sector Virus 2. Multipartite Virus 4. Worm Virus 5. E-mail Virus 6. Macro Virus 7. Script Virus 8. Trojan Horse
- 4. Boot Sector Virus A boot sector virus infects boot sector of computers. During system boot, boot sector virus is loaded into main memory and destroys data stored in hard disk
- 5. Multipartite Virus The multipartite virus are the types of computer viruses that are both a file virus and a boot sector virus. They enter the computer via various sorts of media and then embed themselves in the system memory. They then go into the hard drive and infect the boot sector. Once installed in the boot sector these types of computer viruses infect executable files and spread themselves in the system.
- 6. Worm Virus A worm virus is also a destructive program that fills a computer system with self-replicating information, clogging the system so that its operations are slowed down or stopped
- 8. Macro Virus A macro virus is associated with application software like word and excel. When opening the infected document, macro virus is loaded into main memory and destroys the data stored in hard disk
- 9. Script Virus Commonly found script viruses are written using the Visual Basic Scripting edition (VBS) and the JavaScript programming languages
- 10. Trojan Horse Trojan Horse is a destructive program. It usually pretends as computer games or application software. If executed, computer system will be damaged
- 11. How does it spread Computer viruses spread by attaching themselves to other computer program files. When you exchange a file or pen drive with a virus the virus spreads from one computer to the another.
- 12. Prevention is the best cure Run a secure operating system like UNIX or windows NT. Install virus protection software. Avoid programs from unknown sources. Macro virus protection is enabled in all Microsoft applications. Never double-click on an attachment that contains an executable that arrives as an e-mail attachment.
- 13. Thank You