This document provides an introduction to computer viruses. It defines a computer virus as malicious software that spreads itself to other executable files. The history section outlines some of the earliest viruses, including the Elk Cloner virus from 1982, which was the first PC virus, and the Creeper virus from 1970, which was the first to infect the ARPANET. The document also discusses how viruses are activated in different ways, such as only on specific dates like Friday the 13th, or by receiving instructions while hidden on a computer.

1. VIRUSES
PRESENTED BY : HUMA MALIK
INTRODUCTION TO COMPUTER ( IT-101)

2. GOALS OF PRESENTATION
INTRODUCTION
HISTORY
ACTIVATION

3. INTRODUCTION
VIRUS
VITAL
INFORMATION
RESOURCES
UNDER SIEGE
VERY
IMPORTANT
RESOURCES
UNDER SIEGE

4. A computer virus is a malicious
software that spread itself to the other
executable files and these files are
called as infected files.
DEFINITION
The term
virus was
introduced
by…..
FRED COHEN 1985

5. HISTORY
RICHARD SKRANTA ( 1982 )
Elk cloner was first pc virus he used APPLE II computer
operating system and spread it through FLOPPY DISK.
When his friend used it 50th time it
displayed a short poem.
Bob Thomas ( 1970 )
CREEPER VIRUS was first detected by ARPANET
forerunner of internet. It infected DECPDP-10
running TENEX operating system.
ARPANET copied it self to remote system and
displayed a message ‘’ I AM CREEPER CATCH ME IF
YOU CAN’’ to delete it REEPER was created.
John von Neumann ( 1949 )
He did theoretical work and published it as ‘’
theory and organization of complicated
automata’’.
Theoretical father of computer virology
He created ‘’ self replicating computer
program’’.

6. ACTIVATION
When virus enters
in pc and starts
working is called
activation
• They activate in
different ways.
They are activated
on different date
and days.
• A virus Friday the 13th
is activated only on
same date and day.
They activate in
different ways.
• e.g. trojan stays
hidden in pc and
erase data when it
receives instructions.

7. QUESTIONS????