1. VIRUSES & ANTI- VIRU-SES

2. 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.. CHARACTERISTICS OF A COMPUTER VIRUS:  the ability to replicate itself.  the ability to attach itself to another computer file.

3. WORKING OF COMPUTER VIRUS 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 infected file.

4. TYPES OF COMPUTER VIRUSES SStealth viruses Use certain techniques to avoid detection. MMacro Viruses Infects the macros within a document or template. PPolymorphic viruses Encrypt its code in different ways MMetamorphic viruses Rewrite themselves each time they infect a new file.

5. TROJAN HORSE  Covert  Leaks information  Usually does not reproduce

6. WORMS  Spread over network connection  Worms replicate  First worm released on the Internet was called Morris worm, it was released on Nov 2, 1988.

7. WHAT CAN VIRUSES DO? FFormat hard disk CCopy, rename and delete files MModify files dates and extensions DDisplay false message every few times DDamage data DDamage software

8. SYMPTOMS  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

9. HOW VIRUS SPREADS?  Email Opening and downloading an email containing virus  Networks Connecting with network that contains virus  Removable Storage Media Floppy discs, CDs and flash devices  Pirated Software Installing pirated software that contains virus

10. WHO CREATES VIRUSES AND WHY? Common people: FFor fun RRelease anger TTake revenge FFor fame Profit earners: AAntivirus market Info attackers: DDisrupt enemy’s information and network

11. NOW COMES THE ROLE OF ANTIVIRUSES

12. WHAT DO YOU MEAN BY ANTI-VIRUSES ?  “Antivirus" is protective software designed to defend your computer against malicious software.  In order to be an effective defense, the antivirus software needs to run in the background at all times, and should be kept updated so it recognizes new versions of malicious software.

13. WORKING OF ANTI-VIRUS There are several methods which antivirus software can use to identify malware.  Signature based detection is the most common method. To identify viruses and other malware, antivirus software compares the contents of a file to a dictionary of virus signatures. Because viruses can embed themselves in existing files, the entire file is searched, not just as a whole, but also in pieces. [15]dictionary [15]  Heuristic-based detection, like malicious activity detection, can be used to identify unknown viruses. Heuristic  File emulation is another heuristic approach. File emulation involves executing a program in a virtual environment and logging what actions the program performs. Depending on the actions logged, the antivirus software can determine if the program is malicious or not and then carry out the appropriate disinfection actionsvirtual environment

14. HOW TO PROTECT FROM VIRUS?  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

15. TOP SEVEN ANTIVIRAL PROGRAMS  Kaspersky Antivirus  Net protector Antivirus  Mcafee Antivirus  Symantec Norton Antivirus  Bit Defender 2010  Quick Heal Antivirus  AVG Antivirus

16. GENERAL SECURITY TIPS  Apply user-level security on file sharing when needed.  Don't open email attachments from unknown senders.  Use Rich Text Format files instead of Word Documents.  Updated anti-virus program  Set the BIOS boot sequence  Write protection

17. END !!!!!!!!!!

18. ANY QUERIES ? ? ? ?