Helminthiasis of the Internet
RFC 1135
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RFC - Informational
(December 1989; No errata)
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2013-03-02
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RFC 1135 (Informational)
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Network Working Group J. Reynolds
Request for Comments: 1135 ISI
December 1989
The Helminthiasis of the Internet
Status of this Memo
This memo takes a look back at the helminthiasis (infestation with,
or disease caused by parasitic worms) of the Internet that was
unleashed the evening of 2 November 1988. This RFC provides
information about an event that occurred in the life of the Internet.
This memo does not specify any standard. Distribution of this memo
is unlimited.
Introduction
----- "The obscure we see eventually, the completely
apparent takes longer." ----- Edward R. Murrow
The helminthiasis of the Internet was a self-replicating program that
infected VAX computers and SUN-3 workstations running the 4.2 and 4.3
Berkeley UNIX code. It disrupted the operations of computers by
accessing known security loopholes in applications closely associated
with the operating system. Despite system administrators efforts to
eliminate the program, the infection continued to attack and spread
to other sites across the United States.
This RFC provides a glimpse at the infection, its festering, and
cure. The impact of the worm on the Internet community, ethics
statements, the role of the news media, crime in the computer world,
and future prevention will be discussed. A documentation review
presents four publications that describe in detail this particular
parasitic computer program. Reference and bibliography sections are
also included in this memo.
1. The Infection
----- "Sandworms, ya hate 'em, right??" ----- Michael
Keaton, Beetlejuice
Defining "worm" versus "virus"
A "worm" is a program that can run independently, will consume the
resources of its host from within in order to maintain itself, and
can propagate a complete working version of itself on to other
machines.
Reynolds [Page 1]
RFC 1135 The Helminthiasis of the Internet December 1989
A "virus" is a piece of code that inserts itself into a host,
including operating systems, to propagate. It cannot run
independently. It requires that its host program be run to
activate it.
In the early stages of the helminthiasis, the news media popularly
cited the Internet worm to be a "virus", which was attributed to
an early conclusion of some in the computer community before a
specimen of the worm could be extracted and dissected. There are
some computer scientists that still argue over what to call the
affliction. In this RFC, we use the term, "worm".
1.1 Infection - The Worm Attacks
The worm specifically and only made successful attacks on SUN
workstations and VAXes running Berkeley UNIX code.
The Internet worm relied on the several known access loopholes in
order to propagate over networks. It relied on implementation
errors in two network programs: sendmail and fingerd.
Sendmail is a program that implements the Internet's electronic
mail services (routing and delivery) interacting with remote sites
[1, 2]. The feature in sendmail that was violated was a non-
standard "debug" command. The worm propagated itself via the
debug command into remote hosts. As the worm installed itself in
a new host the new instance began self-replicating.
Fingerd is a utility program that is intended to help remote
Internet users by supplying public information about other
Internet users. This can be in the form of identification of the
full name of, or login name of any local user, whether or not they
are logged in at the time (see the Finger Protocol [3]).
Using fingerd, the worm initiated a memory overflow situation by
sending too many characters for fingerd to accommodate (in the
gets library routine). Upon overflowing the storage space, the
worm was able to execute a small arbitrary program. Only 4.3BSD
VAX machines suffered from this attack.
Another of the worm's methods was to exploit the "trusted host
features" often used in local networks to propagate (using rexec
and rsh).
It also infected machines in /etc/hosts.equiv, machines in
/.rhosts, machines in cracked accounts' .forward files, machines
cracked accounts' .rhosts files, machines listed as network
gateways in routing tables, machines at the far end of point-to-
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RFC 1135 The Helminthiasis of the Internet December 1989
point interfaces, and other machines at randomly guessed addresses
on networks of first hop gateways.
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