worms versus viruses (was Re: Apple ][ worms DO exist!)

[dockery@griffin.cuc.ab.ca (Sean Dockery)]

ag471@yfn.ysu.edu wrote the following article:

| Essentially, a
| Worm is a program that propagates itself through a system destroying
| data.  It does not replicate onto other programs or systems.  A virus,
| on the other hand, may have any number of effects the major one being
| its ability to replicate itself and infect other systems.

  For posterity...  :)

  A virus is a code stub which attaches itself to other programs, and its
usual purpose is to bring a system down (usually on a specified date in
order to give it time to spread.)  Less malevolent viruses don't have a
doomsday date and tend to be more of a nuisance to the user than a danger
to system hardware or data.

  A good example of a virus is the Michaelangelo virus.  On Michaelangelo's
birthday, (I believe that) it erases the boot sector on hard drives
rendering all data on the drive unaccessable.  Fortunately, it was limited
to working on IBM (and clone) platforms.

  A worms does not necessarily have to destroy system data to propagate
itself, and its usual purpose is to consume system resources.  I have never
heard of benevolent worms.

  A good example of a worm is the infamous Internet Worm back in the late
'80s.  In a matter of hours, it had infected over 1/4 of the Internet in
the United States by slipping through a security hole in the standard UUCP
protocol used to transfer data between systems.  The Worm consumed network
resources (which had the side effect of degrading general system
performance to an untolerable level) by using the FTP program in some way,
if I recall correctly.

  The author of the Worm, who created it merely out of curiousity rather
than malice, was shocked at its efficiency and the speed at which his
creation was propagating.  He and another professor at UCB spent two hours
coding the fix and extermintor programs, but unfortunately, the fixes could
not be sent quickly enough to uninfected systems (because the networks
between UCB and the uninfected hosts were already overloaded).

  The hole in the UUCP protocol was patched to prevent anything similar
from happenning again.

  In the end, the author of the Worm was fined over $2M.

| Eric S. Ford	 	   "If you truly love something, set it free.  If it
| ag471@yfn.ysu.edu	   returns, it will be yours forever.  If it doesn't,
| E.Ford6@genie.geis.com	   then hunt it down and kill it!"
-- 
Sean Dockery             |"Now my charms are all o'erthrown, and what strength
dockery@griffin.cuc.ab.ca| I have's mine own." -Prospero, "The Temptest"