Subject Internet Intruder Activity Date 17-feb-92
61faf618195a8f578255d20d3dd845440d85276c83afe6d5b22b4a342f411063
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>> CERT-NL, 01-Mar-2000 <<
>> All CERT-NL information has been moved to http://cert.surfnet.nl. Links <<
>> to CERT-NL information contained in this advisory are therefore outdated. <<
>> <<
>> CERT-NL also has stopped the CERT-CC-Mirror service. Due to this the <<
>> links to the CERT-CC mirror are obsolete. Visit the CERT-CC site for the <<
>> complete CERT-CC advisory texts: http://www.cert.org <<
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Security Advisory CERT-NL
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Author/Source : CERT-NL Index : S-92-03
Distribution : SURFnet Constituency Page : 1
Classification: External Version: final
Subject : Internet Intruder Activity Date : 17-feb-92
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CERT-NL (SURFnet Computer Emergency Response Team) has received
information concerning a security problem in the Internet
CERT-NL wishes to thank CERT/CC for bringing this to our attention.
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CA-92:03 CERT Advisory
February 17, 1992
Internet Intruder Activity
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The Computer Emergency Response Team/Coordination Center (CERT/CC) has
received information regarding a significant intrusion incident on the
Internet. Systems administrators should be aware that many systems on
the Internet have been compromised due to this activity. To identify
whether your systems have been affected by the activity we recommend
that all system administrators check for the signs of intrusion
detailed in this advisory.
This advisory describes the activities that have been identified as
part of this particular incident. This does not address the
possibility that systems may have been compromised due to other,
unrelated intrusion activity.
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I. Description
The intruders gained initial access to a host by discovering a
password for a user account on the system. They then attempted
to become root on the compromised system.
II. Impact
Having gained root access on a system, the intruders installed
trojan binaries that captured account information for both
local and remote systems. They also installed set-uid root
shells to be used for easy root access.
III. Solution
A. Check your systems for signs of intrusion due to this incident.
1. Check the su, ftpd, and ftp binaries (for example, "/bin/su",
"/usr/ucb/ftp" and "/usr/etc/in.ftpd" on Sun systems)
against copies from distribution media.
2. Check for the presence of any of the following files:
"/usr/etc/..." (dot dot dot), "/var/crash/..." (dot dot dot),
"/usr/etc/.getwd", "/var/crash/.getwd", or
"/usr/kvm/..." (dot dot dot).
3. Check for the presence of "+" in the "/etc/hosts.equiv" file.
4. Check the home directory for each entry in the "/etc/passwd"
file for the presence of a ".rhosts" file containing
"+ +" (plus space plus).
5. Search the system for the presence of the following set-uid
root files: "wtrunc" and ".a".
6. Check for the presence of the set-uid root file "/usr/lib/lpx".
B. Take the following steps to secure your systems.
1. Save copies of the identified files to removable media.
2. Replace any modified binaries with copies from
distribution media.
3. Remove the "+" entry from the "/etc/hosts.equiv" file and
the "+ +" (plus space plus) entry from any ".rhosts" files.
4. Remove any of the set-uid root files that you find, which are
mentioned in A5 or A6 above.
5. Change every password on the system.
6. Inspect the files mentioned in A2 above for references
to other hosts.
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If you believe that your system has been compromised, contact CERT/CC or
your representative in FIRST (Forum of Incident Response and Security Teams).
Internet E-mail: cert@cert.sei.cmu.edu
Telephone: 412-268-7090 (24-hour hotline)
CERT/CC personnel answer 7:30 a.m.-6:00 p.m. EST(GMT-5)/EDT(GMT-4),
on call for emergencies during other hours.
Computer Emergency Response Team/Coordination Center (CERT/CC)
Software Engineering Institute
Carnegie Mellon University
Pittsburgh, PA 15213-3890
Past advisories, information about FIRST representatives, and other
information related to computer security are available for anonymous ftp
from cert.sei.cmu.edu (192.88.209.5).
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CERT-NL is the Computer Emergency Response Team for SURFnet customers. SURFnet
is the Dutch network for educational, research and related institutes. CERT-NL
is a member of the Forum of Incident Response and Security Teams (FIRST).
All CERT-NL material is available under:
http://cert.surfnet.nl/
In case of computer or network security problems please contact your local
CERT/security-team or CERT-NL (if your institute is NOT a SURFnet customer
please address the appropriate (local) CERT/security-team).
CERT-NL is one/two hour(s) ahead of UTC (GMT) in winter/summer,
i.e. UTC+0100 in winter and UTC+0200 in summer (DST).
Email: cert-nl@surfnet.nl ATTENDED REGULARLY ALL DAYS
Phone: +31 302 305 305 BUSINESS HOURS ONLY
Fax: +31 302 305 329 BUSINESS HOURS ONLY
Snailmail: SURFnet bv
Attn. CERT-NL
P.O. Box 19035
NL - 3501 DA UTRECHT
The Netherlands
NOODGEVALLEN: 06 22 92 35 64 ALTIJD BEREIKBAAR
EMERGENCIES : +31 6 22 92 35 64 ATTENDED AT ALL TIMES
CERT-NL'S EMERGENCY PHONENUMBER IS ONLY TO BE USED IN CASE OF EMERGENCIES:
THE SURFNET HELPDESK OPERATING THE EMERGENCY NUMBER HAS A *FIXED*
PROCEDURE FOR DEALING WITH YOUR ALERT AND WILL IN REGULAR CASES RELAY IT
TO CERT-NL IN AN APPROPRIATE MANNER. CERT-NL WILL THEN CONTACT YOU.
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