W32.Lofni.Worm

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Discovered: July 14, 2003
Updated: February 13, 2007 12:03:47 PM
Also Known As: W32.Lohack.B.Worm, W32/Noala@MM [McAfee]
Type: Worm
Systems Affected: Windows
CVE References: CVE-2001-0154


W32.Lofni.Worm is a worm that attempts to spread itself through file-sharing networks. It also attempts to mass mail itself to all the contacts in the Windows Address Book. The email will have a variable subject and attachment name. The attachment will have a .exe or .scr file extension.

The worm uses an internal SMTP client engine. In addition, W32.Lofni.Worm is a network-aware worm. It is a Visual Basic application that is compiled to native code and is packed with UPX v1.23.

Definitions dated prior to July 25, 2003 detect this as W32.Lohack.B.Worm.

Antivirus Protection Dates

  • Initial Rapid Release version July 14, 2003
  • Latest Rapid Release version September 28, 2010 revision 054
  • Initial Daily Certified version July 14, 2003
  • Latest Daily Certified version September 28, 2010 revision 036
  • Initial Weekly Certified release date July 16, 2003

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

Writeup By: Sergei Shevchenko

Discovered: July 14, 2003
Updated: February 13, 2007 12:03:47 PM
Also Known As: W32.Lohack.B.Worm, W32/Noala@MM [McAfee]
Type: Worm
Systems Affected: Windows
CVE References: CVE-2001-0154


When W32.Lofni.Worm is executed, it performs the following actions:

  1. Drops the text file, C:\LSSI INFO.txt. The contents of this file is in Spanish.

  2. Displays the contents of the dropped text file in the form with the following caption:


    "Informacion sobre la LSSICE"

  3. Drops these two text files:
    • C:\NO A LA LSSICE.txt
    • C:\i-worm_info.txt

      NOTE: The dropped text files are not malicious.

  4. Drops itself as:
    • C:\Windows_update.exe
    • %Windir%\Explorer.exe

  5. Registers itself as a process to hide its activity under Windows 95/98/Me.

  6. Creates the value:

    "WindowsUpdate"=c:\windows_update.exe"

    in the registry key:

    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run

  7. Retrieves the current user's email address and SMTP server from the registry key:

    HKEY_CURRENT_USER\SOFTWARE\Microsoft\Internet Account Manager\Accounts

  8. Inspects your .NET email account and retrieves the email addresses from the allowed/blocked contacts, by inspecting the following registry entries:

    HKEY_CURRENT_USER\Software\Microsoft\MessengerService\ListCache\.NET Messenger Service

    HKEY_CURRENT_USER\Software\Microsoft\MSNMessenger\ListCache\.NET Messenger Service

  9. Every 10 seconds, checks for an Internet connection by pinging www.microsoft.com.

  10. Adds the values:

    "dir0"="012345:C:\"
    "dir1"="012345:C:\"
    "dir2"="012345:D:\"

    to the registry key:

    HKEY_CURRENT_USER\Software\Kazaa\LocalContent

  11. To let other KaZaA users download these files from C:\ and D:\, the worm drops itself into C:\ and D:\ under the following filenames:
    • Microsoft OfficeXP key Generator.exe
    • MicrosoftWindowsXP key Generator[by_ka0s_te4m].exe
    • Microsoft Universal Crack.exe
    • Macromedia Flash 5 key Generator.exe
    • AdobePhotoshop 7 crack.exe
    • gta3 crack NO CD.exe
    • HackersTools 7.5.exe
    • Tony Hawks pro Skater4!!! crack.exe
    • Macromedia Universal crack.exe
    • Adobe uniVersal crack.exe
    • Unreal Tournament 2003 KeyMaker [by_nobody].exe

  12. May also drop itself into the location pointed to by the value: DlDir0

    which it reads from the registry key:

    HKEY_CURRENT_USER\Software\Kazaa\Transfer

  13. Enumerates network resources and attempts to establish a connection with the unrestricted shares. Then, it attempts to replicate to those shares under the following filenames:
    • www.lssi.es.exe
    • www.mcyt.com.exe
    • ley.pdf.exe
    • resumen.txt.exe
    • texto.txt.exe
    • ley lssi.pdf.exe
    • ley de internet y el comercio electronico.txt.exe
    • que no jueguen con tus libertades.txt.exe
    • texto integro de la lssice.txt.exe
    • NO A LA LSSICE, otra internet es posible.txt.exe
    • www.senado.lssice.es.exe
    • Rg2catdb.exe
    • presentacion.exe
    • downloadit.exe
    • xscreensaver.scr
    • XXX.jpg.exe
    • nuevo_virus_en_internet-LEEME.txt.exe
    • fotos.del.ultimo.viaje.html.exe
    • salvador_de_pantallas.scr
    • README.txt.exe
    • tarifa_plana_DE_VERDAD_ya.html.exe
    • no_queremos_vivir_asi.html.exe
    • por_una_sociedad_mas_justa.html.exe
    • FUERA_la_LSSI.es_INNECESARIA.html.exe
    • vuelve_la_INQUISICION.html.exe
    • NO_al_control_informativo.html.exe
    • NO_a_la_MANIPULACION_informativa.html.exe
    • NO_a_la_CENSURA_informativa.txt.exe
    • NO_queremos_vuestra_ley_INCONSTITUCIONAL.html.exe
    • NO_queremos_vuestra_ley_DISCRIMINATORIA.doc.exe

  14. Attempts to update the run section of the remote file, \Windows\Win.ini.

  15. To gather contacts, the mass-mailing part of the worm inspects the following files:
    • *.wab
    • *.dbx
    • *.mbx
    • *.pst
    • *.pmr
    • *.pmo
    • *.html
    • *.htm

  16. Composes an email message with the following characteristics:
    • Attachment: The attachment is randomly chosen from the following:
      • www.lssi.es.exe
      • www.mcyt.com.exe
      • ley.pdf.exe
      • resumen.txt.exe
      • texto.txt.exe
      • ley lssi.pdf.exe
      • ley de internet y el comercio electronico.txt.exe
      • que no jueguen con tus libertades.txt.exe
      • texto integro de la lssice.txt.exe
      • NO A LA LSSICE, otra internet es posible.txt.exe
      • www.senado.lssice.es.exe
      • Rg2catdb.exe
      • presentacion.exe
      • downloadit.exe
      • xscreensaver.scr
      • FixWin32-hop.a.exe
    • Subject: The subject is randomly chosen from the following:
      • Información sobre la LSSICE
      • Información sobre la LSSICE y sus consecuencias
      • Nuestras libertades en internet en peligro
      • FW:AVISO IMPORTANTE: un nuevo virus llamado LSSICE aparece en internet
      • FW:CAMPAÑA de información sobre la LSSICE
      • Fw:Te reenvío esta presentación que me ha llegado, ya me contarás
      • NUEVO VIRUS muy PELIGROSO
      • Resumen de la ley de internet
      • Nuevas formas de control
      • a las buenas
      • palabrerias
      • importante ACTUALIZACIÓN PARA WINDOWS
      • el fichero que me pediste
      • Acelerador de descargas ultra pequeño!!
      • Salvapantallas cachondisimo
      • PandaSoftware: Nueva utilidad para protegerte de hop.a
    • Message Body: The message is randomly chosen from several hard-coded variants. The text that follows is one of the variants:

      AVISO URGENTE

      PandaSoftware Antivirus acaba de publicar su última herramienta para remover el gusano hop.a Esta herramienta no solo remueve de su sistema el gusano/virus si es encontrado, sino que le protege de posibles infecciones futuras.

      Intrucciones de instalación:

      Ejecutar el fichero adjunto y reiniciar el ordenador

      ----------------------------------------------------
      PandaSoftware Antivirus - http:/ /www.pandasoftware.es

      The message body is composed in HTML format. It may include Jscript that may display one of the following messages:
        • Tal día como hoy, el fenómeno auto-censura comenzó en españa...
        • gracias a la LSSICE (www.lssi.es)
        • este mail está dedicado a todos aquellos que día a día...
        • luchan por recortarnos las libertades enmascarándolo con bonitas palabras
        • Perdón por las molestias. Hasta la próxima
        • para saber más mira la presentación que te adjunto

    • From (The sender's address is spoofed):

      "Ministerio de Ciencia y Tecnologia" <info@myct.es>

      or:

      "Panda Antivirus" <info@myct.es>

      If the message is opened in an unpatched version of Microsoft Outlook or Outlook Express, the attachment may be automatically executed. Information about this vulnerability and a patch are available at: http://www.microsoft.com/technet/security/bulletin/MS01-020.asp.


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: Sergei Shevchenko

Discovered: July 14, 2003
Updated: February 13, 2007 12:03:47 PM
Also Known As: W32.Lohack.B.Worm, W32/Noala@MM [McAfee]
Type: Worm
Systems Affected: Windows
CVE References: CVE-2001-0154


The following 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. Run a full system scan and delete all the files detected as W32.Lofni.Worm.
  4. Delete the value that was 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:
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. 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.Lofni.Worm, click Delete.

4. Deleting the value 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.
  1. Click Start, and then click Run. (The Run dialog box appears.)
  2. Type regedit

    Then click OK. (The Registry Editor opens.)

  3. Navigate to the key:

    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run

  4. In the right pane, delete the value:

    "WindowsUpdate"=c:\windows_update.exe"

  5. Exit the Registry Editor.


Writeup By: Sergei Shevchenko