2.  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.

3.  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.

4. CCovert LLeaks information UUsually does not reproduce

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

6. A computer virus is a malware program that, when executed, replicates by inserting copies of itself (possibly modified) into other computer programs, data files, or the boot sector of the hard drive; when this replication succeeds, the affected areas are then said to be "infected".

8. MMYDOOM SSOBIG.F CCODE RED SSLAMMER

9.  Format hard disk  Copy, rename and delete files  Modify files dates and extensions  Display false message every few times  Damage data  Damage software

11.  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

12.  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

14. CCommon people: For fun Release anger Take revenge For fame PProfit earners: Antivirus market IInfo attackers: Disrupt enemy’s information and network

15. MADE BY : HIMANSHU TYAGI CLASS: VII-B ROLL NO. : 9