1. Submitted By :- Neeraj Kumar Singh Branch :Electronics&communication Topic : computer Viruses Submitted to :- Ms. Veena Gupta

3. A Computer Virus is a program that may disturb the normal working of a computer. CHARACTERISTICS OF A COMPUTER VIRUS:  the ability to replicate itself.  the ability to attach itself to another computer file.

4. The term "computer virus" is often used incorrectly as a catch-all phrase to include all types of Malware such as Computer Worms, Spyware, Adware, and Root kits - all of which are slightly different than Computer Viruses.

5. A Computer Virus needs another program in order to be able to be activated and infect other computers files. For example, a virus might attach itself to a spreadsheet program. Each time the program runs, the virus runs too. A file containing virus is called infested file.

6.  Boot viruses Affects boot sector of a floppy or hard disk.  Program viruses Infect executable program files.  Multipartite viruses A hybrid of Boot and Program viruses.  Directory Virus Directory viruses change the paths that indicate the location of a file

7.  Stealth viruses Use certain techniques to avoid detection.  Macro Viruses Infects the macros within a document or template.  Polymorphic viruses Encrypt its code in different ways  Metamorphic viruses Rewrite themselves each time they infect a new file.

8.  Format hard disk  Copy, rename and dlete files  Modify files dates and extensions  Display false message every few times  Damage data  Damage software

9.  Computer runs slowly  Random restarts  Unknown and uninstalled icons on desktop  Icons change in appearance  System memory and disk space is reduced  New windows open up at an alarming rate  Error messages on regular basis  Files mysteriously disappear

10. EEmail Opening and downloading an email containing virus NNetworks Connecting with network that contains virus RRemovable Storage Media Floppy discs, CDs and flash devices PPirated Software Installing pirated software that contains virus

11. Common people:  For fun  Release anger  Take revenge  For fame Profit earners:  Antivirus market Info attackers:  Disrupt enemy’s information and network

12.  Latest antivirus should be installed  Antivirus software must be upgraded regularly  Unknown emails should not be opened  Unauthorized software should not be installed  Removable storage media should be scanned  Freeware and shareware software from internet should be checked before installing