Computer viruses are malicious programs that attach themselves to other programs to replicate without the user's knowledge. They can cause mischief like displaying nasty messages or deleting files, and even damage computers by overloading them with commands. Viruses spread by infecting removable media like floppy disks and then transferring to other computers when those media are used. Common routes of infection include email attachments and pirated software. Users can protect themselves by backing up files, using prevention rules, and installing anti-virus software that scans for and removes known viruses.

1. Chapter IV COMPUTER VIRUS Mr. Jesus F. Obenita Jr. BBEMNHS-ICT Teacher

2. 5 DEADLIEST VIRUSES

3. WHAT IS A COMPUTER VIRUS? Computer are called viruses beacause they share some of the traits of a biological viruses. A computer virus is a program which attaches itself to, overwrites or otherwise replaces another program in order to reproduce itlself without the knowledge of the user. Since computer viruses are malicious malevolent software, they are called MALWARE.

4. WHY DO PEOPLE CREATE COMPUTER VIRUS? Some people think its funny to create mischief, by creating viruses. Some people are angry. To get revenge, they create viruses to destroy their. Some people are intellectual who to challenge of trying to create a program that replicates itself. Some people want to become famous by inventing viruses People who create viruses tend to immature. May are teenagers or discontended college students.

5. HISTORY 1980 virus spread using personal computer, from business, home, school. The use of the bulletin boards, led to the spread of the virus known TROJAN HORSE. 1983, the first virus created by Fred Cohen. 1986, the virus called the BRAIN. 1987, the JERUSALEM, the 1 st destructive virus.

6. VIRUS MISCHEIF Print nasty messages. Erase some files, or even entire hard disk. Screw up your computer, and stop functioning. Clog your computer, by giving more commands that the computer can handle. PAYLOAD - the damage done by the computer virus.

7. PROPAGATION TRICK They look like a pleasant gift program like the Trojan horse. They purposely delay damaging your computer like the Time bomb.

9. HOW VIRUS SPREADS Booting a PC from an infected medium. Executing an infected program. Opening an infected file.

10. COMMON ROUTES FOR VIRUS Floppy disk or other media that users can exchange. Email attachments. Pirated software. Shareware.

11. HOW INFECTION OCCURS When the code have been executed. Run an infected program, then it copies itself and used unused spaces in your computer.

12. HOW VIRUS WORKS?

13. WHAT ARE SOME VIRUS SYMPTOMS? Slower operation. Decreased memory. Or a disk drive LED lighting up for no apparent reason.

14. ANTI-VIRUS MEASURES Preparation - making back ups of all software. Prevention - creating rules. Detection - use of anti-virus software. Containment - identify and isolate infected items. Recovery - disinfecting or removing infected item, and recovering or replacing corrupted data.

15. ANTI VIRUS SOFTWARE Anti virus software are programs that are installed onto your computer and can scan and remove known viruses. Note: Be sure that you have only one anti virus program running on your computer. POPULAR ANTI VIRUS SOFTWARE Norton Mc Afee AVG

16. End of the Lesson Thank you for Listening