Date: Mon, 14 Dec 1998 17:22:39 -0500
From: CERT Advisory <[email protected]>
To: [email protected]Subject: CERT Summary CS-98.08
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CERT Summary CS-98.08
December 14, 1998
The CERT Coordination Center periodically issues the CERT Summary to
draw attention to the types of attacks currently being reported to our
incident response team, as well as to other noteworthy incident and
vulnerability information. The summary includes pointers to sources of
information for dealing with the problems.
Past CERT Summaries are available from
http://www.cert.org/summaries/
______________________________________________________________________
Recent Activity
Since the last CERT Summary, issued in August 1998 (CS-98.07), we have
seen these trends in incidents reported to us.
1. Vulnerability in mountd
We have seen many reports of this vulnerability being exploited on
NFS servers running certain implementations of mountd, primarily
Linux. On some systems, the vulnerable NFS server is enabled by
default. This vulnerability can be exploited even if the NFS
server does not export any file systems. Intruders who are able to
exploit the vulnerability can do it remotely and can gain
administrative access. We encourage you to review CERT Advisory
CA-98.12, which describes the mountd vulnerability in more detail.
The advisory is available from
http://www.cert.org/advisories/CA-98.12.mountd.html
2. Spread of Windows-Based Trojan Horse Programs
In recent months, we have seen the spread of Windows-based Trojan
horse programs. The most frequently reported incidents involving
Windows-based Trojan horse programs involve the tools Back Orifice
and NetBus.
We receive occasional reports of compromised machines that have
one of these tools installed; however, the majority of reports
involving these tools are from sites noticing intruders scanning
their networks for the presence of these tools. We receive daily
reports indicating that intruders are actively scanning networks
to find running instances of these tools on already compromised
machines.
Look for the following symptoms to detect those scans:
NetBus - connection request (SYN) packets to TCP port 12345
Back Orifice - UDP packets to port 31337
Keep in mind that these tools can be configured to listen on
different ports. Because of this, we encourage you to investigate
any unexplained network traffic.
Because these tools are Trojan horses, users must install them or
be tricked into installing them. To impede the proliferation of
this class of tools, we encourage system administrators to educate
their users about safe computing practices (e.g., only install
software from trusted sources, and use virus scanning software on
any newly introduced software).
For more information about Back Orifice, we encourage you to
review CERT Vulnerability Note VN-98.07.
http://www.cert.org/vul_notes/VN-98.07.backorifice.html
3. Widespread Scans
We continue to receive numerous daily reports of intruders using
tools to scan networks for multiple vulnerabilities. On July 2, we
published an incident note detailing this activity. This document
is available at
http://www.cert.org/incident_notes/IN-98.02.html
Since July 2 these tools have become a bit more sophisticated.
Variants of the "mscan" tool now probe for the most recent
vulnerabilities including
http://www.cert.org/advisories/CA-98.12.mountd.html
Additionally, these tools incorporate the ability to identify a
machine's architecture and operating system.
4. Scripted Tools
Very recently, we have received a few reports indicating that
intruders are executing widespread attacks using scripted tools to
control various information-gathering and exploitation tools. The
combination of functionality used by the scripted tools enables
intruders to automate the process of identifying and exploiting
known vulnerabilities in specific host platforms. This information
is available at
http://www.cert.org/incident_notes/IN-98-06.html
5. Stealth Scanning Techniques
We have received a few reports indicating that intruders are using
stealth scanning techniques. Stealth scanning is used by intruders
to avoid detection. Details about stealth scanning techniques are
available at
http://www.cert.org/incident_notes/IN-98.04.html
__________________________________________________________________
What's New and Updated Since the last CERT Summary, we have
developed new and updated
+ Incident Notes
+ Vulnerability Notes
+ Advisories
+ Vendor-Initated Bulletins
+ System Survivability Research information
+ Incident Response Courses
If you are interested in any of these, please see our What's New
web page for descriptions and links:
http://www.cert.org/nav/whatsnew.html
__________________________________________________________________
CERT/CC Contact Information
Email: [email protected]
Phone: +1 412-268-7090 (24-hour hotline)
Fax: +1 412-268-6989
Postal address:
CERT Coordination Center
Software Engineering Institute
Carnegie Mellon University
Pittsburgh PA 15213-3890
U.S.A.
CERT personnel answer the hotline 08:00-20:00 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.
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To be added to our mailing list for advisories and bulletins, send
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Copyright 1998 Carnegie Mellon University.
Conditions for use, disclaimers, and sponsorship information can
be found in http://www.cert.org/legal_stuff.html.
* CERT is registered in the U.S. Patent and Trademark Office
__________________________________________________________________
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Any material furnished by Carnegie Mellon University and the
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Carnegie Mellon University makes no warranties of any kind, either
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