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Discovered: July 02, 2002
Updated: February 13, 2007 11:49:42 AM
Also Known As: W32.Duni.Worm, WORM_DANDI.A [Trend], Worm/Duni [Vexira], W32/Duni.Worm [NAI], I-Worm.Duni [AVP], W32/Duni-A [Sophos]
Type: Worm
Systems Affected: Windows

W32.Kitro.C.Worm is an Internet worm that can arrive as an email attachment with a .cpl file extension. It copies itself to the windows directory and attempts to spread to the MSN messenger contacts of the user by email.

The original name, W32.Duni.Worm, was derived from a string "unidadworm" that is located in the worm's code.

Antivirus Protection Dates

  • Initial Rapid Release version July 03, 2002
  • Latest Rapid Release version September 28, 2010 revision 054
  • Initial Daily Certified version July 03, 2002
  • Latest Daily Certified version September 28, 2010 revision 036
  • Initial Weekly Certified release date July 03, 2002

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

Writeup By: Patrick Nolan

Discovered: July 02, 2002
Updated: February 13, 2007 11:49:42 AM
Also Known As: W32.Duni.Worm, WORM_DANDI.A [Trend], Worm/Duni [Vexira], W32/Duni.Worm [NAI], I-Worm.Duni [AVP], W32/Duni-A [Sophos]
Type: Worm
Systems Affected: Windows

W32.Kitro.C.Worm arrives by email as an attachment with the .cpl (Control Panel Applet) extension. When executed, it does the following:

It copies itself to the root of the hard drive and to the windows folder (the windows folder is usually c:\windows or c:\winnt). The file name that it uses is a random number with the .cpl extension, for example 1708.cpl.

In order to run each time the machine is rebooted, it adds a value to the key


The value refers to the file that it copied previously, for example

1708     rundll32.exe shell32.dll,Control_RunDLL C:\WINDOWS\1708.cpl

W32.Kitro.C.Worm collects email addresses of the user's MSN messenger contacts from the registry key

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

and attempts to send itself through the SMTP server mail.hotmail.com. The characteristics of the email message are described below. After successfully sending itself, W32.Kitro.C.Worm creates a copy of itself under the name zero.exe in the windows directory.

W32.Kitro.C.Worm uses temporary files named commfig.sys and k32.vxd and located in the windows directory during the manipulation of email addresses lists.

W32.Kitro.C.Worm also attempts to spread through the Kazaa peer-to-peer network. It tries to read the registry value


and if it can do so, it copies itself to the Kazaa share under one of the following names, thus making itself available for other Kazaa users to download.

  • DivResidentEvil.ZIP.cpl
  • SpidermanDesktop.cpl
  • AVP_KeyActualization2002.ZIP .cpl
  • Messenger_skins.ZIP .cpl
  • Porno_sTar.cpl
  • CannibalCorpse.MP3 .cpl
  • ASickofitall.Zip .cpl
  • AXEbahia.cpl
  • NuevosVideosProfesorRossa.cpl
  • NewVideo_Blink182.cpl
  • LagWagon&Blink182.cpl
  • Hacking.cpl
  • AllMcAfeeCrack.Cpl
  • Britney_spearsVSDavidBeckham_AnalPasions.cpl
  • Crack.PerAntivirus.Zip .cpl
  • JamieThomasVSrodneyMullen.cpl
  • MariguanaDesktop.cpl
  • AgeOfEmpires2_Crack.cpl
  • PSX2_Emulation.Zip .cpl
  • GameCube.Zip .cpl
  • Mames.Zip.cpl
  • Crack_Delphi5and6.Zip .cpl
  • terminator2.cpl
  • BinladenF*ckinBillGates.cpl
  • AnalPasswords.cpl
  • ElvisDesktop.cpl
  • B.cpl
  • Z.cpl
  • AVP_Spanish.cpl
  • ZoneAlarmCrack.cpl
  • HardXCore.cpl
  • PhotoShop6.xCrack.cpl
  • BioHazard.cpl
  • VisualBasic.Net.cpl
  • Zidane.Taliban.cpl
  • VideoPortoSeguro.cpl
  • PSX2EmulatorFree.Zip .cpl
  • sexo_en_la_calle.cpl
  • sexo_anal_full_video.cpl
  • sexo_oriental_full_video.cpl
  • muertes_videos.cpl
  • fullvideo_anal_action.zip .cpl

In order to evade detection by some antivirus products, W32.Kitro.C.Worm manipulates data files and registry information. It modifies the registry value


to point to the windows directory and alters the value


probably in an attempt to prevent an antivirus program from running on startup.

In addition it deletes the following files if they are present on the system:

C:\program files\perav\pav.dll
C:\program files\perav\per.dll

and also the following files from the windows folder:


W32.Kitro.C.Worm contains several possible email formats, using various subject lines and file attachments.

Possible Subjects lines:
  • Esta si que es zorra!!!
  • Fotos de asesinatos, Jack el Destripador, Charles Manson, y muchos mas para decorar tu escritorio.
  • Yeahhh Mutha Facka... NY Brookling in your NET.
  • Genera passwords para poder entrar a las webs mas putonas de la red, y gratis, incluso podras bajar peliculas porno.
  • Para los verdaderos amigos...
  • Test de amor.
  • 30 pregutas para saber si tu pareja te enga
  • !La imagen de cristo en un bosque.
  • mira como seria un mundial en la antigua mesopotamia.
  • Fotos de Cristo para decorar tu escritorio.
  • Te han enviado una postal.
  • Te acuerdas de mi?
  • Asi se hace el amor...
  • Asi me gusta a mi...
  • Esto doleria mucho, mucho :-).
  • Si esto no me lo regresas me sentire mal.
  • La vida despues de la muerte.
  • Me cambie de correo, aver si ahora me escribes...
  • Leelo y reenvialo a quienes mas amas.
  • Cancion de amor, para ti.
  • Paulina Rubio y su zorrita cosmica...
  • No todo lo que uno lea sobre el servicio de webmail de Microsoft es cierto.
  • !Ver el listado de falsas alarmas.
  • !ja, la han cagado con este video.
  • Bin Laden DT de la seleccion de arabia...
  • Bin Laden nuevo goliador de Arabia saudita , jaaaaaaa.
  • Bin Laden presidente de la FIFA.
  • Dime que te parece esta animacion.
  • Una broma para las secretarias, ja ja.
  • Test para secretarias, para saber que tan tontas son.
  • 41 preguntas para saber si alguien es sicopata.
  • mira esto es mas ordinario que gato con hanta, juaaaaaaaaaaaa.
  • listado de ultimas mentiras que circulan por los mails.
  • Last hoaxes list.
  • Hola
  • como te gustarian este par de tetitas.
  • Leelo y reenvialo a quienes mas amas.
  • mira esto es mas ordinario que gato con hanta, juaaaaaaaaaaaa.
  • listado de ultimas mentiras que circulan por los mails.
  • Bin Laden killing muthaFaka bill gates.
  • mira como seria un mundial en la antigua mesopotamia

Possible corresponding attachments:
  • zorrita.cpl
  • jack.cpl
  • sickofitall.cpl
  • analpasswords.cpl
  • poema_angelical.cpl
  • testdeamor.cpl
  • Adulterio_en_tus_narices.cpl
  • Cristo.cpl
  • mundial.cpl
  • cristo2002.cpl
  • postal_de_mi_alma.cpl
  • estesoyyo.cpl
  • milposiciones.cpl
  • como_como.cpl
  • por_ahi_noooooo.cpl
  • lomasimportante.cpl
  • vidaymuerte.cpl
  • siemprevivir@setnet.cpl
  • milvidas.cpl
  • comoolvidarte.cpl
  • paulinasex.cpl
  • mentiras_en_hotmail.cpl
  • listado_de_hoaxes.cpl
  • zapato_en_el_culo.cpl
  • binladenDT.cpl
  • gooooooool.cpl
  • Fifaladen.cpl
  • 788782.cpl
  • secretarias.cpl
  • test_secretontas.cpl
  • sere_yo_uno_de_esos.cpl
  • scarycrai.cpl
  • mentiras_mails.cpl
  • mcaffehoaxlist.cpl
  • tetris2002.cpl
  • zandias_meloones.cpl
  • quien_como_tu.cpl
  • portymore.cpl
  • listado_de_porquerias.cpl
  • billgatesscream.cpl


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: Patrick Nolan

Discovered: July 02, 2002
Updated: February 13, 2007 11:49:42 AM
Also Known As: W32.Duni.Worm, WORM_DANDI.A [Trend], Worm/Duni [Vexira], W32/Duni.Worm [NAI], I-Worm.Duni [AVP], W32/Duni-A [Sophos]
Type: Worm
Systems Affected: Windows

NOTE: These instructions are for all current and recent Symantec antivirus products, including the Symantec AntiVirus and Norton AntiVirus product lines.

  1. Update the virus definitions, run a full system scan, and delete all files that are detected as W32.Kitro.C.Worm
  2. Delete the value that looks similar to

    rundll32.exe shell32.dll,Control_RunDLL C:\WINDOWS\1708.cpl

    from the registry key

  3. Also delete the value


   from the regsitry key


For details on how to do this, read the following instructions.

NOTE: Before proceeding, Windows Me and Windows XP users should temporarily turn off System Restore. This feature, which is enabled by default, is used by Windows Me/XP to restore files on your computer in case they become damaged. When a computer is infected with a virus, worm, or Trojan, it is possible that the virus, worm, or Trojan could be backed up by System Restore. By default, Windows prevents System Restore from being modified by outside programs. As a result, there is the possibility that you could accidentally restore an infected file, or that on-line scanners would detect the threat in that location. 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 Anti-Virus Tools Cannot Clean Infected Files in the _Restore Folder , Article ID: Q263455

To scan for and delete the infected files:
  1. Obtain the most recent virus definitions. There are two ways to do this:
    • Run LiveUpdate, which is the easiest way to obtain virus definitions. These virus definitions have undergone full quality assurance testing by Symantec Security Response and are posted to the LiveUpdate servers one time each week (usually Wednesdays) unless there is a major virus outbreak. To determine whether definitions for this threat are available by LiveUpdate, look at the Virus Definitions (LiveUpdate) line at the top of this write-up.
    • Download the definitions using the Intelligent Updater. Intelligent Updater virus definitions have undergone full quality assurance testing by Symantec Security Response. They are posted on U.S. business days (Monday through Friday). They must be downloaded from the Symantec Security Response Web site and installed manually. To determine whether definitions for this threat are available by the Intelligent Updater, look at the Virus Definitions (Intelligent Updater) line at the top of this write-up.

      Intelligent Updater virus definitions are available here. For detailed instructions on how to download and install the Intelligent Updater virus definitions from the Symantec Security Response Web site, click here.
  2. Start your Symantec antivirus software and make sure that it is configured to scan all files.
  3. Run a full system scan.
  4. If any files are detected as infected by W32.Kitro.C.Worm, click Delete.

To remove the values from the registry:

CAUTION : Symantec strongly recommends that you back up the registry before you make any changes to it. Incorrect changes to the registry can result in permanent data loss or corrupted files. Modify only the keys that are specified. Read the document How to make a backup of the Windows registry for instructions.
  1. Click Start, and click Run. The Run dialog box appears.
  2. Type regedit and then click OK. The Registry Editor opens.
  3. Navigate to the following key:

  4. In the right pane, locate the value that looks similar to the following example and delete it:

    rundll32.exe shell32.dll,Control_RunDLL C:\WINDOWS\1708.cpl
  5. Next, Navigate to the following key:

  6. In the right pane, locate the value that looks similar to the following example and delete it:

  7. Click Registry, and click Exit.

Writeup By: Patrick Nolan