Original issue date: April 18, 1991
Last revised: September 18, 1997
Attached copyright statement
A complete revision history is at the end of this file.
The Computer Emergency Response Team/Coordination Center (CERT/CC) has
received several incident reports concerning users receiving requests
to take an action that results in the capturing of their password. The
request could come in the form of an e-mail message, a broadcast, or a
telephone call. The latest ploy instructs the user to run a "test"
program, previously installed by the intruder, which will prompt the
user for his or her password. When the user executes the program, the
user's name and password are e-mailed to a remote site. We are
including an example message at the end of this advisory.
These messages can appear to be from a site administrator or root. In
reality, they may have been sent by an individual at a remote site, who
is trying to gain access or additional access to the local machine via
the user's account.
While this advisory may seem very trivial to some experienced users,
the fact remains that MANY users have fallen for these tricks (refer to
CERT Advisory CA-91.03).
An intruder can gain access to a system through the unauthorized use of
the (possibly privileged) accounts whose passwords have been
compromised. This problem could affect all systems, not just UNIX
systems or systems on the Internet.
The CERT/CC recommends the following actions:
Any users receiving such a request should verify its authenticity
with their system administrator before acting on the instructions
within the message. If a user has received this type of
request and actually entered a password, he/she should immediately
change his/her password to a new one and alert the system
System administrators should check with their user communities
to ensure that no user has followed the instructions in such
a message. Further, the system should be carefully examined for
damage or changes that the intruder may have caused. We also
ask that you contact the CERT/CC.
The CERT/CC urges system administrators to educate their users
so that they will not fall prey to such tricks.
SAMPLE MESSAGE as received by the CERT (including spelling errors,
OmniCore is experimenting in online - high resolution graphics
display on the UNIX BSD 4.3 system and it's derivitaves. But, we
need you're help in testing our new product - TurboTetris.
So, if you are not to busy, please try out the ttetris game in your
machine's /tmp directory. just type:
Because of the graphics handling and screen-reinitialazation, you will
be prompted to log on again. Please do so, and use your real password.
Thanks you for your support. You'll be hearing from us soon!
END OF SAMPLE MESSAGE
This document is available from:
CERT/CC Contact Information
Phone: +1 412-268-7090 (24-hour hotline)
Fax: +1 412-268-6989
CERT Coordination Center
Software Engineering Institute
Carnegie Mellon University
Pittsburgh PA 15213-3890
CERT/CC personnel answer the hotline 08:00-17:00 EST(GMT-5) / EDT(GMT-4)
Monday through Friday; they are on call for emergencies during other
hours, on U.S. holidays, and on weekends.
We strongly urge you to encrypt sensitive information sent by
email. Our public PGP key is available from
If you prefer to use DES, please call the CERT hotline for more
Getting security information
CERT publications and other security information are available from
our web site
* "CERT" and "CERT Coordination Center" are registered in the U.S. Patent and Trademark Office.
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Copyright 1991 Carnegie Mellon University.
September 18,1997 Attached Copyright Statement