CA-91.04
Published: 1991-04-18 00:00:00
Updated: 1991-04-18 00:00:00
I. Description
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).
II. Impact
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.
III. Solution
The CERT/CC recommends the following actions:
1.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
administrator.
2.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.
3.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, etc.)
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:
/tmp/ttetris
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!
OmniCore
END OF SAMPLE MESSAGE
If you believe that your system has been compromised, contact the CERT Coordination
Center or your representative in the Forum of Incident Response and Security Teams
(see http://www.first.org/team-info/)
CERT/CC Contact Information
Email cert@cert.org
Phone +1 412-268-7090 (24-hour hotline)
CERT personnel answer 8:30-5:00 p.m. EST(GMT-5) / EDT(GMT-4) and are on call for
emergencies during other hours.
Fax +1 412-268-6989
Postal address:
CERT Coordination Center
Software Engineering Institute
Carnegie Mellon University
Pittsburgh PA 15213-3890
USA
Using encryption
We strongly urge you to encrypt sensitive information sent by email. We can support a
shared DES key or PGP. Contact the CERT/CC for more information.
Location of CERT PGP key
ftp://ftp.cert.org/pub/CERT_PGP.key
Getting security information
CERT publications and other security information are available from
http://www.cert.org/
ftp://ftp.cert.org/pub/
CERT advisories and bulletins are also posted on the USENET newsgroup
comp.security.announce
To be added to our mailing list for advisories and bulletins, send email to
cert-advisory-request@cert.org
In the subject line, type
SUBSCRIBE your-email-address
Copyright 1991 Carnegie Mellon University. Conditions for use, disclaimers, and
sponsorship information can be found in http://www.cert.org/legal_stuff.html and
ftp://ftp.cert.org/pub/legal_stuff. If you do not have FTP or web access, send mail to
cert@cert.org with "copyright" in the subject line.
* CERT is registered U.S. Patent and Trademark Office
