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Subject:
From:
Gary Peirce <[log in to unmask]>
Reply To:
Date:
Tue, 12 Aug 2003 09:05:04 -0400
Content-Type:
text/plain
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text/plain (329 lines)
Be advised that windowsupdate.com may be acting slowly.

We have historically filtered most of these ports into our system
although this does not prevent the spread from an inside
compromised host.

Taking a quick look, UM hosts I see as possibly infected currently
sourcing scans on port 135. There are probably many more.
Admins responsible for the machines, please repair them.
See notes below - check for Mblast.exe running as a process.

130.111.8.49
130.111.74.61
130.111.73.94
130.111.73.35
130.111.69.113
130.111.50.42
130.111.226.149
130.111.223.80
130.111.204.76
130.111.164.62
130.111.164.208
130.111.155.172
130.111.147.22
130.111.146.82
130.111.145.112
130.111.133.121
130.111.131.27
130.111.12.40
130.111.105.130


>
> -----BEGIN PGP SIGNED MESSAGE-----
>
> CERT Advisory CA-2003-20 W32/Blaster worm
>
>    Original issue date: August 11, 2003
>    Last revised: --
>    Source: CERT/CC
>
>    A complete revision history is at the end of this file.
>
> Systems Affected
>
>      * Microsoft Windows NT 4.0
>      * Microsoft Windows 2000
>      * Microsoft Windows XP
>      * Microsoft Windows Server 2003
>
> Overview
>
>    The  CERT/CC  is receiving reports of widespread activity related
>    to a new piece of malicious code known as W32/Blaster. This worm
>    appears to exploit  known  vulnerabilities in the Microsoft Remote
>    Procedure Call (RPC) Interface.
>
> I. Description
>
>    The  W32/Blaster worm exploits a vulnerability in Microsoft's DCOM
>    RPC interface  as  described  in VU#568148 and CA-2003-16. Upon
>    successful execution,   the  worm  attempts  to  retrieve  a  copy
>    of  the  file msblast.exe  from  the compromising host. Once this
>    file is retrieved, the  compromised  system  then  runs  it and
>    begins scanning for other vulnerable  systems to compromise in the
>    same manner. In the course of propagation,  a TCP session to port
>    135 is used to execute the attack. However,  access  to  TCP  ports
>     139  and 445 may also provide attack vectors  and should be
>    considered when applying mitigation strategies. Microsoft  has
>    published  information  about  this  vulnerability  in Microsoft
>    Security Bulletin MS03-026.
>
>    Lab testing has confirmed that the worm includes the ability to
>    launch a TCP SYN flood denial-of-service attack against
>    windowsupdate.com. We are  investigating  the  conditions  under
>    which  this  attack  might manifest  itself.  Unusual  or
>    unexpected traffic to windowsupdate.com may  indicate an infection
>    on your network, so you may wish to monitor network traffic.
>
>    Sites  that do not use windowsupdate.com to manage patches may wish
>    to block  outbound traffic to windowsupdate.com. In practice, this
>    may be difficult  to  achieve, since windowsupdate.com may not
>    resolve to the same    address    every   time.   Correctly
>    blocking   traffic   to windowsupdate.com  will require detailed
>    understanding of your network routing  architecture,  system
>    management  needs, and name resolution environment. You should not
>    block traffic to windowsupdate.com without a thorough understanding
>    of your operational needs.
>
>    We  have  been in contact with Microsoft regarding this possibility
>    of this denial-of-service attack.
>
> II. Impact
>
>    A  remote  attacker  could  exploit  these  vulnerabilities to
>    execute arbitrary   code   with   Local   System  privileges  or
>    to  cause  a denial-of-service condition.
>
> III. Solutions
>
> Apply patches
>
>    All users are encouraged to apply the patches referred to in
>    Microsoft Security  Bulletin  MS03-026  as soon as possible in
>    order to mitigate the  vulnerability  described  in  VU#568148.
>    These  patches are also available via Microsoft's Windows Update
>    service.
>
>    Systems  running  Windows  2000  may still be vulnerable to at
>    least a denial-of-service  attack  via  VU#326746 if their DCOM RPC
>    service is available  via the network. Therefore, sites are
>    encouraged to use the packet  filtering  tips  below  in  addition
>    to  applying the patches supplied in MS03-026.
>
>    It  has been reported that some affected machines are not able to
>    stay connected  to  the  network  long  enough  to  download
>    patches  from Microsoft.  For  hosts  in  this situation, the
>    CERT/CC recommends the following:
>     1. Physically disconnecting the system from the network
>     2. Check the system for signs of compromise.
>           + In most cases, an infection will be indicated by the
>           presence
>             of the registry key
>             "HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVers
>             ion \Run\windows  auto  update"  with  a value of
>             msblast.exe. If this key is present, remove it using a
>             registry editor.
>     3. If  you're  infected,  terminate  the  running copy of
>     msblast.exe
>        using the Task Manager.
>     4. Take  one of the following steps to protect against the
>     compromise
>        prior to installing the Microsoft patch:
>           + Disable DCOM as described below
>           + Enabling  Microsoft's  Internet  Connection  Filter (ICF),
>           or
>             another host-level packet filtering program to block
>             incoming connections for 135/tcp
>     5. Reconnect  the  system to the network and apply the patches in
>     the
>        recommended manner
>
>    Trend  Micro,  Inc.  has  published a set of steps to accomplish
>    these goals.  Symantec has also published a set of steps to
>    accomplish these goals.
>
> Disable DCOM
>
>    Depending  on  site  requirements,  you  may  wish  to disable DCOM
>    as described  in  MS03-026. Disabling DCOM will help protect
>    against this vulnerability  but may also cause undesirable side
>    effects. Additional details  on  disabling DCOM and possible side
>    effects are available in Microsoft Knowledge Base Article 825750.
>
> Filter network traffic
>
>    Sites are encouraged to block network access to the following
>    relevant ports   at  network  borders.  This  can  minimize  the
>    potential  of denial-of-service  attacks originating from outside
>    the perimeter. The specific services that should be blocked include
>      * 69/UDP
>      * 135/TCP
>      * 135/UDP
>      * 139/TCP
>      * 139/UDP
>      * 445/TCP
>      * 445/UDP
>      * 4444/TCP
>
>    Sites  should  consider  blocking both inbound and outbound traffic
>    to these  ports,  depending  on  network  requirements,  at  the
>    host and network level. Microsoft's Internet Connection Firewall
>    can be used to accomplish these goals.
>
>    If  access  cannot  be  blocked  for  all  external hosts, the
>    CERT/CC recommends  limiting  access  to  only those hosts that
>    require it for normal  operation. As a general rule, the CERT/CC
>    recommends filtering all  types  of  network  traffic  that  are
>    not  required  for normal operation.
>
>    Because  current exploits for VU#568148 create a backdoor, which is
>    in some  cases  4444/TCP, blocking inbound TCP sessions to ports on
>    which no  legitimate  services  are  provided  may  limit intruder
>    access to compromised hosts.
>
> Recovering from a system compromise
>
>    If  you  believe  a  system under your administrative control has
>    been compromised, please follow the steps outlined in
>
>           Steps for Recovering from a UNIX or NT System Compromise
>
> Reporting
>
>    The  CERT/CC  is tracking activity related to this worm as
>    CERT#30479. Relevant  artifacts  or activity can be sent to
>    [log in to unmask] with the appropriate CERT# in the subject line.
>
> Appendix A. Vendor Information
>
>    This  appendix  contains information provided by vendors. When
>    vendors report  new  information,  this section is updated and the
>    changes are noted  in  the  revision  history. If a vendor is not
>    listed below, we have not received their comments.
>
> Microsoft
>
>      Please see Microsoft Security Bulletin MS03-026.
>
> Appendix B. References
>
>      * CERT/CC Advisory CA-2003-19 -
>        http://www.cert.org/advisories/CA-2003-19.html
>      * CERT/CC Vulnerability Note VU#561284 -
>        http://www.kb.cert.org/vuls/id/561284
>      * CERT/CC Vulnerability Note VU#326746 -
>        http://www.kb.cert.org/vuls/id/326746
>      * Microsoft Security Bulletin MS03-026 -
>        http://microsoft.com/technet/security/bulletin/MS03-026.asp
>      * Microsoft      Knowledge      Base      article      823980
>       -
>        http://support.microsoft.com?kbid=823980
>
> Thanks
>
>    Our  thanks  to Microsoft Corporation for their review of and input
>    to this advisory.
>    ___________________________________________________________________
>    ___
>
>    Authors:  Chad  Dougherty,  Jeffrey  Havrilla, Shawn Hernan, and
>    Marty Lindner
>    ___________________________________________________________________
>    ___
>
>    This document is available from:
>    http://www.cert.org/advisories/CA-2003-20.html
>    ___________________________________________________________________
>    ___
>
> CERT/CC Contact Information
>
>    Email: [log in to unmask]
>           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/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.
>
> 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  subscribe  to  the CERT mailing list for advisories and
>    bulletins, send  email  to [log in to unmask] Please include in
>    the body of your message
>
>    subscribe cert-advisory
>
>    *  "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 2003 Carnegie Mellon University.
>
>    Revision History
>
>    August 11, 2003: Initial release
>
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>
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>


Garry Peirce   [log in to unmask]   1-207-581-3539
============================================
==                   Network Analyst
==     UNET Technology Services, Network Operations
==              University of Maine System
============================================

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