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 1
/ Sept. / 2001 :
Hurry to finished
documents for HA,
also Power point
presentation for OR too, funny !!
6 / Sept. / 2001
:
Upgrade my floppy
disk & Harddisk to 20 GB, after format HD
I can see 8.2
GB,This problem came from my mainboard so old !
Must upgrade
to new too,So sad I must change again after
change so many
times before.
So funny but
sad come true !
10 / Sept. / 2001
:
Fed up with
someone,
about take their
jobs with Big Mouth not their real job.
How will you
do about this situation,
Try to provident
or try to endure ?? ( Ahoy !! )
11 / Sept. / 2001
:
Day of Terror
at USA ;
Two Airplanes
drive to strike at World Trade Center ( New york city )
and Pentagon
( Washington D.C. )
about
08.20 AM ( 08.20 PM time in Thailand )
Very frightfull,
why they do that ?
* Nobody know
about you better than you,
If you
wanna know so well just ask yourself.
This short messages
to say how deeply grived I was to hear
of the
Terrorism Hits America, It's a terrible grief
which
come upon you and American,
but I
know you will be sustained by God,
Please
accept my sincere and deep sympathy.
13 / Sept. / 2001
:
Pre survey OR
HatYai Hospital before HA visit last year.
19 / Sept. / 2001
:
Found something
wrong about e-mails at PC'OR
show many *.eml
after delete will come after restart,
must delete
all *.eml
Sysadmin told
me that it's not serious,
huh ! why he
think like that :-(
Next time call
W32.Nimda.A@m, Please contact
http://www.thaicert.nectec.or.th
or http://www.cert.org
This message
below sent to me on 18 Sept.,2001 from CERT ,
but I read this
e-mail so late.:-(
So that I don't
know why
*** PGP
Signature Status: bad
........for
me Tell me too.
-----BEGIN
PGP SIGNED MESSAGE-----
CERT Advisory
CA-2001-26 Nimda Worm
Original release
date: September 18, 2001
Source: CERT/CC
A complete
revision history is at the end of this file.
Systems Affected
* Systems running
Microsoft Windows 95, 98, ME, NT, and 2000
Overview
The CERT/CC
has received reports of new malicious code known as the
"W32/Nimda worm" or the "Concept Virus (CV) v.5."
This new worm
appears to spread by multiple mechanisms:
* from client
to client via email
* from client
to client via open network shares
* from web
server to client via browsing of compromised web sites
* from client
to web server via active scanning for and exploitation
of the "Microsoft IIS 4.0 / 5.0 directory traversal" vulnerability
(VU #111677)
* from client
to web server via scanning for the back doors left
behind by the "Code Red II" (IN-2001-09), and "sadmind/IIS"
(CA-2001-11) worms
Initial analysis
indicates that the worm contains no destructive
payload beyond modification of web content to facilitate its own
propagation.
We are also
receiving reports of denial of service as a result of
network scanning and email propagation.
I. Description
The Nimda worm
has the potential to affect both user workstations
(clients) running Windows 95, 98, ME, NT, or 2000 and servers running
Windows NT and 2000.
Email Propagation
This worm propagates
through email arriving as a MIME
"multipart/alternative" message consisting of two sections.
The first
section is defined as MIME type "text/html", but it contains
no text,
so the email appears to have no content. The second section is defined
as MIME type "audio/x-wav", but it contains a base64-encoded
attachment named "readme.exe", which is a binary executable.
Due to a vulnerability
described in CA-2001-06 (Automatic Execution of
Embedded MIME Types), any mail software running on an x86 platform
that uses Microsoft Internet Explorer 5.5 SP1 or earlier (except
IE
5.01 SP2) to render the HTML mail automatically runs the enclosed
attachment and, as result, infects the machine with the worm. Thus,
in
vulnerable configurations, the worm payload will automatically be
triggered by simply opening (or previewing) this mail message. As
an
executable binary, the payload can also be triggered by simply running
the attachment.
The email message
delivering the Nimda worm appears to also have the
following characteristics:
* The text
in the subject line of the mail message appears to be
variable, but those seen to date have been over 80 characters
long.
* There appear
to be many slight variations in the attach binary
file, causing the MD5 checksum to be different when one compares
different attachments from different email messages. However, the
file length of the attachment appears to consistently be 57344
bytes.
Payload
Infected client
machines attempt to send copies of the Nimda worm via
email to all addresses found in the Windows address book.
Likewise, the
client machines begin scanning for vulnerable IIS
servers. Nimda looks for backdoors left by previous IIS worms: Code
Red II [IN-2001-09] and sadmind/IIS worm [CA-2001-11]. It also
attempts to exploit the IIS Directory Traversal vulnerability (VU
#111677). The selection of potential target IP addresses follows
these
rough probabilities:
* 50% of the
time, an address with the same first two octets will be
chosen
* 25% of the
time, an address with the same first octet will be
chosen
* 25% of the
time, a random address will be chosen
The infected
client machine transfers a copy of the Nimda code to any
server that it scans and finds to be vulnerable. Once running on
the
server machine, the worm traverses each directory in the system
(including all those accessible through a file shares) and write
a
copy of itself to disk using the name "README.EML". When
a directory
containing web content (e.g., HTML or ASP files) is found, the
following snippet of Javascript code is appended to every one of
these
web-related files:
<script
language="JavaScript">
window.open("readme.eml", null, "resizable=no,top=6000,left=6000")
</script>
This modification
of web content allows further propagation of the
worm to new clients through a browser or browsing of a network file
system.
Browser Propagation
As part of
the infection process, the Nimda worm modifies all web
content files it finds (including, but not limited to, files with
.htm, .html, and .asp extensions). As a result, any user browsing
web
content on the system, whether via the file system or via a web
server, may download a copy of the worm. Some browsers may
automatically execute the downloaded copy, thereby infecting the
browsing system.
File System
Propagation
The Nimda worm
creates numerous copies of itself (using the name
README.EML) in all writable directories (including those found on
a
network share) to which the user has access. If a user on another
system subsequently selects the copy of the worm file on the shared
network drive in Windows Explorer with the preview option enabled,
the
worm may be able to compromise that system.
System FootPrint
The scanning
activity of the Nimda worm produces the following log
entries for any web server listing on port 80/tcp:
GET /scripts/root.exe?/c+dir
GET /MSADC/root.exe?/c+dir
GET /c/winnt/system32/cmd.exe?/c+dir
GET /d/winnt/system32/cmd.exe?/c+dir
GET /scripts/..%5c../winnt/system32/cmd.exe?/c+dir
GET /_vti_bin/..%5c../..%5c../..%5c../winnt/system32/cmd.exe?/c+dir
GET /_mem_bin/..%5c../..%5c../..%5c../winnt/system32/cmd.exe?/c+dir
GET
/msadc/..%5c../..%5c../..%5c/..\xc1\x1c../..\xc1\x1c../..\xc1\x1c../winnt/system
32/cmd.exe?/c+dir
GET /scripts/..\xc1\x1c../winnt/system32/cmd.exe?/c+dir
GET /scripts/..\xc0/../winnt/system32/cmd.exe?/c+dir
GET /scripts/..\xc0\xaf../winnt/system32/cmd.exe?/c+dir
GET /scripts/..\xc1\x9c../winnt/system32/cmd.exe?/c+dir
GET /scripts/..%35c../winnt/system32/cmd.exe?/c+dir
GET /scripts/..%35c../winnt/system32/cmd.exe?/c+dir
GET /scripts/..%5c../winnt/system32/cmd.exe?/c+dir
GET /scripts/..%2f../winnt/system32/cmd.exe?/c+dir
Note: The first
four entries in these sample logs denote attempts to
connect to the backdoor left by Code Red II, while the remaining
log
entries are examples of exploit attempts for the Directory Traversal
vulnerability.
II. Impact
Intruders can
execute arbitrary commands within the LocalSystem
security context on machines running the unpatched versions of IIS.
Host that have been compromised are also at high risk for being
party
to attacks on other Internet sites.
The high scanning
rate of the Nimda worm may also cause bandwidth
denial-of-service conditions on networks with infected machines.
III. Solutions
Recommendations
for System Administrators of IIS machines
To determine
if your system has been compromised, look for the
following:
* root.exe
artifact (indicates a compromise by Code Red II or
sadmind/IIS worms making the system vulnerable to the Nimda worm)
* admin.dll
artifact or unexpected .eml files in the directories
with web content (indicates compromise by the Nimda worm)
The only safe
way to recover from the system compromise is to format
the system drive(s) and reinstall the system software from trusted
media (such as vendor-supplied CD-ROM). Additionally, after the
software is reinstalled, all vendor-supplied security patches must
be
applied. The recommended time to do this is while the system is
not
connected to any network. However, if sufficient care is taken to
disable all server network services, then the patches can be
downloaded from the Internet.
Detailed instructions
for recovering your system can be found in the
CERT/CC tech tip:
Steps for Recovering
from a UNIX or NT System Compromise
http://www.cert.org/tech_tips/win-UNIX-system_compromise.html
Apply the appropriate
patch from your vendor
A cumulative
patch which addresses all of the IIS-related
vulnerabilities exploited by the Nimda worm is available from
Microsoft at
http://www.microsoft.com/technet/security/bulletin/MS01-044.asp
Recommendations
for End User Systems
Apply the appropriate
patch from your vendor
If you are
running a vulnerable version of Internet Explorer (IE), the
CERT/CC recommends applying patch for the "Automatic Execution
of
Embedded MIME Types" vulnerability available from Microsoft
at
http://www.microsoft.com/technet/security/bulletin/MS01-020.asp
Run and Maintain
an Anti-Virus Product
It is important
for users to update their anti-virus software. Most
anti-virus software vendors have released updated information, tools,
or virus databases to help detect and partially recover from this
malicious code. A list of vendor-specific anti-virus information
can
be found in Appendix A.
Many anti-virus
packages support automatic updates of virus
definitions. We recommend using these automatic updates when
available.
Don't open
e-mail attachments
The Nimda worm
may arrive as an email attachment named "readme.exe".
Users should not open this attachment.
Disable JavaScript
End-user systems can become infected with the
Nimda worm by browsing web sites hosted by infected servers. This
method of infection requires the use of JavaScript to be successful.
Therefore, the CERT/CC recommends that end user systems disable
JavaScript.
Appendix A.
Vendor Information
Antivirus Vendor
Information
Central Command,
Inc.
http://support.centralcommand.com/cgi-bin/command.cfg/php/endus
er/std_adp.php?p_refno=010918-000005
Command Software
Systems
http://www.commandsoftware.com/virus/nimda.html
Data Fellows
Corp
http://www.datafellows.com/v-descs/nimda.shtml
McAfee
http://vil.mcafee.com/dispVirus.asp?virus_k=99209&
Sophos
http://www.sophos.com/virusinfo/analyses/w32nimdaa.html
Symantec
http://www.symantec.com/avcenter/venc/data/w32.nimda.a@mm.html
Trend Micro
http://www.antivirus.com/vinfo/virusencyclo/default5.asp?VName=
TROJ_NIMDA.A
http://www.antivirus.com/pc-cillin/vinfo/virusencyclo/default5.
asp?VName=TROJ_NIMDA.A
You may wish
to visit the CERT/CC's computer virus resources page
located at
http://www.cert.org/other_sources/viruses.html
References
Authors: Roman
Danyliw, Chad Dougherty, Allen Householder, Robin
Ruefle
______________________________________________________________________
This document
is available from:
http://www.cert.org/body/advisories/CA200126_FA200126.html
______________________________________________________________________
CERT/CC Contact
Information
Email: cert@cert.org
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.
Using encryption
We strongly
urge you to encrypt sensitive information sent by email.
Our public PGP key is available from
http://www.cert.org/CERT_PGP.key
If you prefer
to use DES, please call the CERT hotline for more
information.
Getting security
information
CERT publications
and other security information are available from
our web site
http://www.cert.org/
To be added
to our mailing list for advisories and bulletins, send
email to cert-advisory-request@cert.org and include SUBSCRIBE
your-email-address in the subject of your message.
* "CERT"
and "CERT Coordination Center" are registered in the U.S.
Patent and Trademark Office.
______________________________________________________________________
NO WARRANTY
Any material furnished by Carnegie Mellon University and the Software
Engineering Institute is furnished on an "as is" basis.
Carnegie
Mellon University makes no warranties of any kind, either expressed
or
implied as to any matter including, but not limited to, warranty
of
fitness for a particular purpose or merchantability, exclusivity
or
results obtained from use of the material. Carnegie Mellon University
does not make any warranty of any kind with respect to freedom from
patent, trademark, or copyright infringement.
_________________________________________________________________
Conditions
for use, disclaimers, and sponsorship information
Copyright 2001
Carnegie Mellon University.
Revision History
September 18,
2001: Initial Release
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21 / Sept. / 2001
:
Thank You Party
Meeting at HatYai Hospital,
Very funny but
I got many jobs wait to finished.
27 / Sept. / 2001
:
Waiting for
GPRS ; General Packet Radio Service.
New technolog
from AIS.
3rd Generation
Technology.
.. / Sept. /
2001 : To be
Continue !
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