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From: csrobe@ICASE.EDU (Charles S. [Chip] Roberson)
Newsgroups: comp.sys.atari.st
Subject: Re: Virus 101 - Chapter 1
Message-ID: <8903150434.AA22458@icase.edu>
Date: 15 Mar 89 04:34:36 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
Organization: The Internet
Lines: 65

Before you take this as gospel...

>Some basic terms, as they have come to be used in this area: 

>A VIRUS is any program which spreads itself secretly. It may be
>destructive, a prank, or even intended to be helpful, but it spreads. 

>A TROJAN HORSE is a program which executes one function secretly while
>appearing to be accomplishing some other task, or appearing to be some
>other program entirely. One task a Trojan Horse may accomplish is to
>install a virus, which would then spread itself.

>A WORM is a program or function which imbeds itself inside another
>program, be it an application, part of a system, a library or
>whatever. It may or may not spread itself by some means, and may or
>may not have destructive intents. 

Take a look at these definitions from Eugene H. Spafford's tech report
CSD-TR-823 "The Internet Worm Program: An Analysis":

Members of the press have used the term 'virus', possibly becuase their
experience to date has been only with that form of security problem.
This usage has been reinforced by quotes from computer managers and
programmers also unfamiliar with the terminology.  For purposes of
clarifying the terminology, let me define the difference between these
two terms and give some citations to their origins:

	A 'worm' is a program that can run by itself and can propagate
	a fully working version of itself to other machines.  It is derived
	from the word 'tapeworm', a parasitic organism that lives inside
	a host and saps its resources to maintain itself.

	A 'virus' is a piece of code that adds itself to other programs,
	including operating systems.  It cannot run independently -- it
	requires that its 'host' program be run to activate it.  As such,
	it has a clear analog to biological  viruses -- those viruses are
	not considered alive in the usual sense; instead, they invade host
	cells and corrupt them, causing them to produce new viruses.

The program that was loosed on the Internet was clearly a worm.

The concept of a worm program that spreads itself from machine to machine
was apparently first described by John Brunner in 1975 in his classic science
fiction novel _The_Shockwave_Rider_. [....]

The first use of the word 'virus' (to my knowledge) to describe something that
infects a computer was by David Gerrold in his science fiction short stories
about the G.O.D. machine.  These stories were later combined and expanded to
form a book _When_Charlie_Was_One_. [....]

----------
Just thought I'd try to clarify things, a bit.
cheers,
-c


|Chip Roberson                ARPANET:  csrobe@cs.wm.edu                  |
|Dept of Comp. Sci.                     csrobe@icase.edu                  |
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