W32.HLLW.Southghost

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Discovered: November 28, 2003
Updated: February 13, 2007 12:14:24 PM
Type: Worm
Systems Affected: Windows


W32.HLLW.Southghost a worm that spreads through email and file-sharing networks.

The email has the following characteristics:

Subject: Espero que te llege a tiempo...
Attachment: BuenasNuevas.doc.pif

The worm is written in Microsoft Visual Basic and packed with Petite.

Antivirus Protection Dates

  • Initial Rapid Release version December 01, 2003
  • Latest Rapid Release version September 28, 2010 revision 054
  • Initial Daily Certified version December 01, 2003
  • Latest Daily Certified version September 28, 2010 revision 036
  • Initial Weekly Certified release date December 03, 2003

Click here for a more detailed description of Rapid Release and Daily Certified virus definitions.

Writeup By: Kaoru Hayashi

Discovered: November 28, 2003
Updated: February 13, 2007 12:14:24 PM
Type: Worm
Systems Affected: Windows


When W32.HLLW.Southghost is executed, it performs the following actions:

  1. Creates following folders:
    • C:\KaZaA\My Shared Folder
    • C:\edonkey2000\incoming
    • C:\icq\shared files

  2. Deletes following files:
    • C:\Windows\Regedit.exe
    • C:\Windows\Scanregw.exe
    • C:\Windows\System\Msconfig.exe
    • C:\Windows\System\Sfc.exe

  3. Copies itself as following:
    • %System%\Regsrv32.com
    • %Windows%\System.com
    • %Windows%\Regedit.exe
    • %Windows%\System\Msconfig.exe
    • %Windows%\System\Texto 3D.scr
    • %Windows%\System\Windows volando.scr
    • %Windows%\System\Objetos 3D.scr
    • %Windows%\System\Laberinto 3D.scr
    • %Windows%\System\Tuberas 3D.scr
    • %Windows%\System\Figuras en 3D.scr
    • %Windows%\GHoST_Vrl.worm
    • %Windows%\System\Curvas y colores.scr
    • %Windows%\System\Formas y figuras.scr
    • %Windows%\System\Marquesina desplazndose.scr
    • %Windows%\System\Mis imgenes.scr
    • %Windows%\System\Pantalla neutra.scr
    • %Windows%\System\Volando por el espacio.scr
    • C:\Mis documentos\Shakira.scr
    • C:\Windows\Escritorio\WebCamS.pif
    • C:\Windows\System\Texto 3D.scr
    • C:\Windows\System\Windows volando.scr
    • C:\Windows\System\Objetos 3D.scr
    • C:\Windows\System\Laberinto 3D.scr
    • C:\Windows\System\Tuberas 3D.scr
    • C:\Windows\System\Figuras en 3D.scr
    • C:\Windows\System\Curvas y colores.scr
    • C:\Windows\System\Formas y figuras.scr
    • C:\Windows\System\Marquesina desplazndose.scr
    • C:\Windows\System\Mis imgenes.scr
    • C:\Windows\System\Pantalla neutra.scr
    • C:\Windows\System\Volando por el espacio.scrC:\Autoexec.com
    • C:\Mis documentos\BruceLee.com
    • C:\BuenasNuevas.doc.pif
    • C:\Mis documentos\NoLeer.bat
    • C:\KaZaA\My Shared Folder\Hotmail Hack Crack 2003.exe
    • C:\KaZaA\My Shared Folder\Listado de Msica 2003.com
    • C:\KaZaA\My Shared Folder\Shakira and Britney Screen Saver.scr
    • C:\KaZaA\My Shared Folder\Norton and McAffe Antivirus 2003 KeyGen Crack.exe
    • C:\edonkey2000\incoming\Hotmail_mail_hack.exe
    • C:\edonkey2000\incoming\Norton and McAffe Antivirus 2003 KeyGen Crack.exe.exe
    • C:\edonkey2000\incoming\Age_of_Mythology_Crack.exe
    • C:\edonkey2000\incoming\Listado de Msica 2003.exe
    • C:\icq\shared files\Norton and McAffe Antivirus 2003 KeyGen Crack.exe
    • C:\icq\shared files\Music 2003 List.exe
    • C:\icq\shared files\Shakira and Britney Screen Saver 2003.scr
    • C:\icq\shared files\Hotmail_hack_guide.exe
    • A:\Horoscopo2003.exe
    • A:\INSTALL.EXE
    • A:\SETUP.EXE
    • A:\INSTALAR.EXE
    • C:\ARCHIVOS DE PROGRAMA\PERAV\PAV.EXE
    • C:\ARCHIVOS DE PROGRAMA\PERAV\PER.EXE
    • C:\ARCHIVOS DE PROGRMA\PERAV\INSTALAR.EXE
    • C:\ARCHIVOS DE PROGRAMA\PERAV\PERUPD.EXE
    • C:\ARCHIVOS DE PROGRAMA\PERAV\PAVMAIL.EXE
    • C:\ARCHIVOS DE PROGRAMA\PERAV\TSKWIZAR.EXE
    • C:\ARCHIVOS DE PROGRAMA\PERAV\DOWNLOAD.EXE
    • C:\ARCHIVOS DE PROGRAMA\THE HACKER\THAV.EXE
    • C:\ARCHIVOS DE PROGRAMA\THE HACKER\TH32.EXE
    • C:\ARCHIVOS DE PROGRAMA\THE HACKER\TH32UPD.EXE
    • C:\ARCHIVOS DE PROGRAMA\THE HACKER\THMAIL.EXE
    • C:\ARCHIVOS DE PROGRAMA\THE HACKER\UNINST.EXE
    • D:\GHoST.exe
    • D:\WIN98SE\INSTALL.EXE
    • D:\WIN98SE\SETUP.EXE
    • D:\WIN98SE\INSTALAR.EXE
    • E:\WIN98SE\INSTALL.EXE
    • E:\WIN98SE\SETUP.EXE
    • E:\WIN98SE\INSTALAR.EXE
    • F:\WIN98SE\INSTALL.EXE
    • F:\WIN98SE\SETUP.EXE
    • F:\WIN98SE\INSTALAR.EXE

  4. Adds the values:
    • <executed file name>="%System%\Regsrv32.com"
    • "REGEDIT"="%System%\Regsrv32.com"

      to the registry key:

      HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\
      RunService

      so that the worm runs when you start Windows.
  5. Modifies the shell= command in the C:\Windows\System.ini file to:

    shell=explorer.exe system.com

  6. Adds following line in the C:\Windows\System.ini file:

    SCREENSAVE.EXE=C:\Windows\System\Texto 3D.scr

  7. Sends email to Windows Messenger and MSN Messenger users.

  8. The email has the following characteristics:

    From: lindaflorcita__22@hotmail.com
    Subject: Espero que te llege a tiempo...
    Message:
    Hola, no sabes cuantas buenas y malas noticias te tengo que
    dar, al ser tantas la escribo en un
    documento, que esta adjunto
    a este mail, espero que lo leas y me des animospara
    afrontar estos ultimos hechos...
    Attachment: BuenasNuevas.doc.pif


Recommendations

Symantec Security Response encourages all users and administrators to adhere to the following basic security "best practices":

  • Use a firewall to block all incoming connections from the Internet to services that should not be publicly available. By default, you should deny all incoming connections and only allow services you explicitly want to offer to the outside world.
  • 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.
  • Ensure that programs and users of the computer use the lowest level of privileges necessary to complete a task. When prompted for a root or UAC password, ensure that the program asking for administration-level access is a legitimate application.
  • Disable AutoPlay to prevent the automatic launching of executable files on network and removable drives, and disconnect the drives when not required. If write access is not required, enable read-only mode if the option is available.
  • Turn off file sharing if not needed. If file sharing is required, use ACLs and password protection to limit access. Disable anonymous access to shared folders. Grant access only to user accounts with strong passwords to folders that must be shared.
  • Turn off and remove unnecessary services. By default, many operating systems install auxiliary services that are not critical. These services are avenues of attack. If they are removed, threats have less avenues of attack.
  • If a 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.
  • Configure your email server to block or remove email that contains file attachments that are commonly used to spread threats, such as .vbs, .bat, .exe, .pif and .scr files.
  • Isolate compromised computers quickly to prevent threats from spreading further. 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.
  • If Bluetooth is not required for mobile devices, it should be turned off. If you require its use, ensure that the device's visibility is set to "Hidden" so that it cannot be scanned by other Bluetooth devices. If device pairing must be used, ensure that all devices are set to "Unauthorized", requiring authorization for each connection request. Do not accept applications that are unsigned or sent from unknown sources.
  • For further information on the terms used in this document, please refer to the Security Response glossary.

Writeup By: Kaoru Hayashi

Discovered: November 28, 2003
Updated: February 13, 2007 12:14:24 PM
Type: Worm
Systems Affected: Windows



These instructions pertain to all current and recent Symantec antivirus products, including the Symantec AntiVirus and Norton AntiVirus product lines.

  1. Disable System Restore (Windows Me/XP).
  2. Update the virus definitions.
  3. Restart the computer in Safe mode or VGA mode.
  4. Run a full system scan and delete all the files detected as W32.HLLW.Southghost.
  5. Restore the overwritten files.
  6. Reverse the changes that the worm added to the registry.
  7. Edit the changes to the System.ini file.
For specific details on each of these procedures, 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:
Note: When you are completely finished with the removal procedure, and you are satisfied that the threat has been removed, you should reenable System Restore by following the instructions in the aforementioned documents.

For additional information, and an alternative to disabling Windows Me System Restore, see the Microsoft Knowledge Base article, "Antivirus Tools Cannot Clean Infected Files in the _Restore Folder ," Article ID: Q263455.

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 VGA mode
Shut down the computer and turn off the power. Wait for at least 30 seconds, and then restart the computer in Safe mode or VGA mode.
  • For Windows 95, 98, Me, 2000, or XP users, restart the computer in Safe mode. For instructions, read the document, "How to start the computer in Safe Mode."
  • For Windows NT 4 users, restart the computer in VGA mode.
4. Scanning for and deleting the infected files
  1. Start your Symantec antivirus program and make sure that it is configured to scan all the files.
  2. Run a full system scan.
  3. If any files are detected as infected with W32.HLLW.Southghost, click Delete.

5. Restoring deleted or overwritten files
Restore the following files overwritten by the worm from the backup, if necessary:
  • C:\Windows\Regedit.exe
  • C:\Windows\Scanregw.exe
  • C:\Windows\System\Msconfig.exe
  • C:\Windows\System\Sfc.exe
The following documents provide general instructions on how to extract files. This information is provided for your convenience. The exact steps may slightly vary depending on the configuration of your operation system, the location of the files, and so on. For additional information, read the Help files, contact Microsoft, or refer to the following Windows documentation:
6. Deleting the value from the registry

WARNING: 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.
  1. Click Start, and then click Run. (The Run dialog box appears.)
  2. Type regedit, and then click OK. (The Registry Editor opens.)
  3. Navigate to the following key:

    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\RunService
  4. In the right pane, delete the values:
    • <executed file name>="%System%\Regsrv32.com"
    • "REGEDIT"="%System%\Regsrv32.com"
  5. Click Registry, and click Exit.

7. Editing the System.ini file
If you are running Windows 95/98/Me, follow these steps:
  1. The function you perform depends on your operating system:
    • Windows 95/98: Go to step b.
    • Windows Me: If you are running Windows Me, the Windows Me file-protection process may have made a backup copy of the System.ini file that you need to edit. If this backup copy exists, it will be in the C:\Windows\Recent folder. Symantec recommends that you delete this file before continuing with the steps in this section. To do this:
      1. Start Windows Explorer.
      2. Browse to and select the C:\Windows\Recent folder.
      3. In the right pane, select the System.ini file and delete it. The System.ini file will be regenerated when you save your changes to it in step f.

  2. Click Start, and then click Run.
  3. Type the following, and then click OK.

    edit c:\windows\system.ini

    (The MS-DOS Editor opens.)

    NOTE: If Windows is installed in a different location, the worm did not modify system.ini, and you can skip this step.

  4. In the [boot] section of the file, look for a line similar to:

    shell = Explorer.exe system.com

  5. If this line exists, delete everything to the right of Explorer.exe.

    When you are done, it should look like:

    shell = Explorer.exe
  6. In the [boot] section of the file, look for a line similar to:

    SCREENSAVE.EXE=C:\Windows\System\Texto 3D.scr

  7. Delete the line.

  8. Click File, and then click Save.

  9. Click File, and then click Exit.




Writeup By: Kaoru Hayashi