CRIME SOBIG ADVISORY

From: Jim Wood (jwood@private)
Date: Tue Aug 19 2003 - 13:34:33 PDT

  • Next message: Daggett, Steve: "CRIME 80/20 Rule"

    FYI-
    
    
    Network traffic is up due to the SOBIG worm today.  Numerous reports
    from security sites, as well as network admins around the country are
    reporting the attachment coming in as a .pif attachment to their email
    clients.
    
    The following information is from Symantec, just thought I would pass it
    along in the interest of being pro-active in the shadow of the last
    mess.
    
    **********************************START
    DOCUMENT****************************
    
     Symantec Security Response http://securityresponse.symantec.com 
    W32.Sobig.F@mm   
    Discovered on: August 19, 2003  
    Last Updated on: August 19, 2003 09:24:02 AM 
    
    Due to the number of submissions received from customers, Symantec
    Security Response has upgraded this threat to a Category 3 from a
    Category 2 threat. 
    W32.Sobig.F@mm is a mass-mailing, network-aware worm that sends itself
    to all the email addresses that it finds in the files with the following
    extensions:
    
    
    .dbx 
    .eml 
    .hlp 
    .htm 
    .html 
    .mht 
    .wab 
    .txt
    
    The worm utilizes it's own SMTP engine to propagate and will attempt to
    create a copy of itself on accessible network shares.
    
    Email Routine Details
    The email message has the following characteristics:
    
    From: Spoofed address (which means that the sender in the "From" field
    is most likely not the real sender). 
    The worm may use the address admin@private as the sender.
    
    Subject: 
    Re: Details 
    Re: Approved 
    Re: Re: My details 
    Re: Thank you! 
    Re: That movie 
    Re: Wicked screensaver 
    Re: Your application 
    Thank you! 
    Your details
    
    Body: 
    See the attached file for details 
    Please see the attached file for details.
    
    Attachment: 
    your_document.pif 
    document_all.pif 
    thank_you.pif 
    your_details.pif 
    details.pif 
    document_9446.pif 
    application.pif 
    wicked_scr.scr 
    movie0045.pif
    
    NOTE: The worm deactivates on September 10, 2003. The last day on which
    the worm will spread is September 9, 2003.
    
    Also Known As:  Sobig.F [F-Secure], W32/Sobig.f@MM [McAfee], WORM
    SOBIG.F [Trend] 
      
    Type:  Worm 
    Infection Length:  about 72,000 bytes 
      
      
      
    Systems Affected:  Windows 2000, Windows 95, Windows 98, Windows Me,
    Windows NT, Windows XP 
    Systems Not Affected:  Linux, Macintosh, OS/2, UNIX, Windows 3.x 
      
      
      
    
    
     
    Beta Virus Definitions
     August 18, 2003 
     
     
    Virus Definitions (Intelligent Updater) *
     August 19, 2003 
     
     
    Virus Definitions (LiveUpdate™) **
     August 19, 2003 
     
     
    *
     Intelligent Updater definitions are released daily, but require manual
    download and installation. Click here to download manually.
     
    **
     LiveUpdate virus definitions are usually released every Wednesday.
    Click here for instructions on using LiveUpdate.
     
     
     
    
    
    
    
    Wild: 
    
    Number of infections: 0 - 49 
    Number of sites: 3 - 9 
    Geographical distribution: Low 
    Threat containment: Easy 
    Removal: Easy 
     Threat Metrics
     
             
    Wild:
    Medium
     Damage:
    Low
     Distribution:
    Medium
     
     
    
    
    
    When W32.Sobig.F@mm is executed, it performs the following actions:
    
    
    Copies itself as %Windir%\winppr32.exe.
    
    NOTE: %Windir% is a variable. The worm locates the Windows installation
    folder (by default, this is C:\Windows or C:\Winnt) and copies itself to
    that location.
    
    
    Creates the file, %Windir%\winsst32.dat.
    
    
    Adds the value:
    
    "TrayX"="%Windir%\winppr32.exe /sinc"
    
    to the registry key:
    
    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    
    so the worm runs when you start Windows.
    
    Attempts to copy itself to any network shares it has write access to.
    The worm will utilize standard Windows API's to do this.
    
    Sobig.F can download arbitrary files to an infected computer and execute
    them. The author of the worm has used this functionality to steal
    confidential system information and to set up spam relay servers on
    infected computers. 
    
    This functionality may also be used as a worm self-update feature. Under
    the correct conditions, Sobig.F attempts to contact one of the list of
    master servers, which the author of the worm controls. Then, the worm
    retrieves a URL that it uses to determine where to get the Trojan file,
    downloads the Trojan file to the local computer, and then executes it.
    
    In Sobig.F, the conditions for this download attempt are: 
    According to UTC time, the day of the week must be Monday or Friday. 
    According to UTC time, the time of day must be between 7:00 P.M. and
    11:59:59 P.M.
    
    Sobig.F obtains the UTC time through the NTP protocol, by contacting one
    of several possible servers on port 123/udp (the NTP port).
    
    The worm starts the download attempt by sending a probe to port 8998/udp
    of the master server. Then, the server replies with a URL, where the
    worm can download the file to execute.
    
    Sobig.F also opens the following ports: 
    995/udp 
    996/udp 
    997/udp 
    998/udp 
    999/udp
    
    and it listens for any incoming UDP datagrams on these ports. Incoming
    datagrams are parsed, and upon receiving a datagram with the proper
    signature, the master server list of the worm may be updated.
    
    Network administrators should do the following: 
    Block inbound traffic on ports 99x/udp. 
    Block outbound traffic on port 8998/udp. 
    Monitor NTP requests (port 123/udp), as these could be coming from
    infected computers. (The frequency of such checks for an infected
    computer should be once per hour.)
    
    
    
    
    
    
    Symantec Security Response encourages all users and administrators to
    adhere to the following basic security "best practices":
    
    Turn off and remove unneeded services. By default, many operating
    systems install auxiliary services that are not critical, such as an FTP
    server, telnet, and a Web server. These services are avenues of attack.
    If they are removed, blended threats have less avenues of attack and you
    have fewer services to maintain through patch updates. 
    If a blended threat exploits one or more network services, disable, or
    block access to, those services until a patch is applied. 
    Always keep your patch levels up-to-date, especially on computers that
    host public services and are accessible through the firewall, such as
    HTTP, FTP, mail, and DNS services. 
    Enforce a password policy. Complex passwords make it difficult to crack
    password files on compromised computers. This helps to prevent or limit
    damage when a computer is compromised. 
    Configure your email server to block or remove email that contains file
    attachments that are commonly used to spread viruses, such as .vbs,
    .bat, .exe, .pif and .scr files. 
    Isolate infected computers quickly to prevent further compromising your
    organization. Perform a forensic analysis and restore the computers
    using trusted media. 
    Train employees not to open attachments unless they are expecting them.
    Also, do not execute software that is downloaded from the Internet
    unless it has been scanned for viruses. Simply visiting a compromised
    Web site can cause infection if certain browser vulnerabilities are not
    patched. 
    
    
    The following instructions pertain to all current and recent Symantec
    antivirus products, including the Symantec AntiVirus and Norton
    AntiVirus product lines.
    
    NOTE: If you are on a network or have a full-time connection to the
    Internet, disconnect the computer from the network and the Internet.
    Remove this threat from all the computers on the network before
    reconnecting to it. Disable or password-protect file sharing before
    reconnecting the computers to the network or to the Internet. 
    
    For instructions on how to do this, see your Windows documentation, or
    the document, "How to configure shared Windows folders for maximum
    network protection."
    
    IMPORTANT: Do not skip this step. Disconnect from the network before
    attempting to remove this worm.
    
    
    Disable System Restore (Windows Me/XP). 
    Update the virus definitions. 
    Do one of the following: 
    Windows 95/98/Me: Restart the computer in Safe mode. 
    Windows NT/2000/XP: End the Trojan process.
    Run a full system scan and delete all the files detected as
    W32.Sobig.F@mm. 
    Delete the values that were added to the registry.
    
    For specific details on each of these steps, read the following
    instructions.
    
    1. Disabling System Restore (Windows Me/XP)
    If you are running Windows Me or Windows XP, we recommend that you
    temporarily turn off System Restore. Windows Me/XP uses this feature,
    which is enabled by default, to restore the files on your computer in
    case they become damaged. If a virus, worm, or Trojan infects a
    computer, System Restore may back up the virus, worm, or Trojan on the
    computer.
    
    Windows prevents outside programs, including antivirus programs, from
    modifying System Restore. Therefore, antivirus programs or tools cannot
    remove threats in the System Restore folder. As a result, System Restore
    has the potential of restoring an infected file on your computer, even
    after you have cleaned the infected files from all the other locations.
    
    Also, a virus scan may detect a threat in the System Restore folder even
    though you have removed the threat.
    
    For instructions on how to turn off System Restore, read your Windows
    documentation, or one of the following articles: 
    "How to disable or enable Windows Me System Restore" 
    "How to turn off or turn on Windows XP System Restore"
    
    2. Updating the virus definitions
    Symantec Security Response fully tests all the virus definitions for
    quality assurance before they are posted to our servers. There are two
    ways to obtain the most recent virus definitions: 
    Running LiveUpdate, which is the easiest way to obtain virus
    definitions: These virus definitions are posted to the LiveUpdate
    servers once each week (usually on Wednesdays), unless there is a major
    virus outbreak. To determine whether definitions for this threat are
    available by LiveUpdate, refer to the Virus Definitions (LiveUpdate). 
    Downloading the definitions using the Intelligent Updater: The
    Intelligent Updater virus definitions are posted on U.S. business days
    (Monday through Friday). You should download the definitions from the
    Symantec Security Response Web site and manually install them. To
    determine whether definitions for this threat are available by the
    Intelligent Updater, refer to the Virus Definitions (Intelligent
    Updater).
    
    The Intelligent Updater virus definitions are available: Read "How to
    update virus definition files using the Intelligent Updater" for
    detailed instructions.
    
    3. Restarting the computer in Safe mode or ending the Trojan process 
    Windows 95/98/Me
    Restart the computer in Safe mode. All the Windows 32-bit operating
    systems, except for Windows NT, can be restarted in Safe mode. For
    instructions, read the document, "How to start the computer in Safe
    Mode."
    
    Windows NT/2000/XP
    To end the Trojan process: 
    Press Ctrl+Alt+Delete once. 
    Click Task Manager. 
    Click the Processes tab. 
    Double-click the Image Name column header to alphabetically sort the
    processes. 
    Scroll through the list and look for Winppr32.exe. 
    If you find the file, click it, and then click End Process. 
    Exit the Task Manager.
    
    4. Scanning for and deleting the infected files 
    Start your Symantec antivirus program and make sure that it is
    configured to scan all the files. 
    For Norton AntiVirus consumer products: Read the document, "How to
    configure Norton AntiVirus to scan all files." 
    For Symantec AntiVirus Enterprise products: Read the document, "How to
    verify that a Symantec Corporate antivirus product is set to scan all
    files." Run a full system scan. 
    If any files are detected as infected with W32.Sobig.F@mm, click Delete.
    
    
    5. Deleting the values from the registry
    
    CAUTION: Symantec strongly recommends that you back up the registry
    before making any changes to it. Incorrect changes to the registry can
    result in permanent data loss or corrupted files. Modify the specified
    keys only. Read the document, "How to make a backup of the Windows
    registry," for instructions. 
    
    Click Start, and then click Run. (The Run dialog box appears.) 
    Type regedit 
    
    Then click OK. (The Registry Editor opens.)
    
    
    Navigate to the key:
    
    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    
    
    In the right pane, delete the value:
    
    "TrayX"="%Windir%\winppr32.exe /sinc"
    
    
    Exit the Registry Editor.
    
    
     
    
    
    Write-up by: Benjamin Nahorney and Atli Gudmundsson 
    
    
    ********************END DOCUMENT********************************
    
    Jim Wood
    jwood@private
    MW Technology Group Inc
    DBA:  Zebra Computer Repair & Networking
    360-736-7000
     
    
    
    ---
    Outgoing mail is certified Virus Free.
    Checked by AVG anti-virus system (http://www.grisoft.com).
    Version: 6.0.509 / Virus Database: 306 - Release Date: 8/12/2003
    
    Jim Wood
    jwood@private
    MW Technology Group Inc
    DBA:  Zebra Computer Repair & Networking
    360-736-7000
     
    
    
    ---
    Outgoing mail is certified Virus Free.
    Checked by AVG anti-virus system (http://www.grisoft.com).
    Version: 6.0.509 / Virus Database: 306 - Release Date: 8/12/2003
     
    



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