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Discovered: June 12, 2003
Updated: February 13, 2007 12:02:35 PM
Also Known As: W32/Anacon-D [Sophos], I-Worm.Nocana.f [KAV], W32/Naco.f@MM [McAfee], W32/Naco.F@mm [Frisk], PE_NACO.F [Trend], Win32.Naco.E [CA]
Type: Worm
Systems Affected: Microsoft IIS, Windows

W32.Naco.D@mm is a variant of W32.Naco@mm. W32.Naco.D@mm is a mass-mailing worm that attempts to spread itself by email and file-sharing networks. The worm also contains a Backdoor functionality and attempts to replace HTML files on the Microsoft IIS server.

This variant, unlike previous variants, can also infect files. The code for W32.Naco.D@mm is buggy, and therefore, may infect the same files multiple times.

W32.Naco.D@mm is written in the Microsoft Visual Basic (VB) programming language and has been compiled to P-Code. Thus, The VB run-time libraries are required to execute W32.Naco.D@mm.

The worm has been packed and obfuscated using a known run-time compression utility, which appears to be an attempt to make it more difficult to analyze the threat.

When W32.Naco.D@mm is executed, it will attempt to display two messages with the titles:

  • Anacon 6 WOrm
  • Anacon 6

Antivirus Protection Dates

  • Initial Rapid Release version June 12, 2003
  • Latest Rapid Release version March 03, 2008 revision 035
  • Initial Daily Certified version June 12, 2003
  • Latest Daily Certified version March 03, 2008 revision 037
  • Initial Weekly Certified release date June 18, 2003

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

Writeup By: Neal Hindocha

Discovered: June 12, 2003
Updated: February 13, 2007 12:02:35 PM
Also Known As: W32/Anacon-D [Sophos], I-Worm.Nocana.f [KAV], W32/Naco.f@MM [McAfee], W32/Naco.F@mm [Frisk], PE_NACO.F [Trend], Win32.Naco.E [CA]
Type: Worm
Systems Affected: Microsoft IIS, Windows

W32.Naco.D@mm has been encrypted and compressed using a known run-time packing utility. All the text strings in the compiled executable have been encrypted. This appears to be an attempt by the author to make it more difficult to analyze the worm.

W32.Naco.D@mm contains a large number of bugs, and because of them, you may notice the following behavior when the worm executes:

  • The worm may enter what appears to be an infinite loop, which may cause all the functions (described below) to repeat.
    • Some functions, such as the termination of security products from memory, may not occur at all.
    • Some functions work differently than what the author of this worm intended.
  • The system may become unstable and stop working after the worm has been running for a certain period of time.
  • As the infection routine will be executed a multiple of times, and the infected files do not have an infection marker, the files will be infected multiple times. This causes the files to grow to a large size.
  • The worm may not run at all, and instead, it may crash the system.

When W32.Naco.D@mm is executed, it will attempt to do the following.
  1. Display the following two messages:


  2. Attempt to infect the executable files in the %System% folder.

    NOTE: %System% is a variable. The worm locates the System folder and copies itself to that location. By default, this is C:\Windows\System (Windows 95/98/Me), C:\Winnt\System32 (Windows NT/2000), or C:\Windows\System32 (Windows XP).

  3. Copy itself to the %System% folder as Csrss32.exe.

  4. Add the value:


    to the registry key:


  5. Add the value:


    to the registry key:


  6. Add the value:


    to the registry key:


  7. Add the values:


    to the registry key:


  8. Attempt to terminate the following processes:
    • Zonealarm.exe
    • Wfindv32.exe
    • Webscanx.exe
    • Vsstat.exe
    • Vshwin32.exe
    • Vsecomr.exe
    • Vscan40.exe
    • Vettray.exe
    • Vet95.exe
    • Tds2-Nt.exe
    • Tds2-98.exe
    • Tca.exe
    • Tbscan.exe
    • Sweep95.exe
    • Sphinx.exe
    • Smc.exe
    • Serv95.exe
    • Scrscan.exe
    • Scanpm.exe
    • Scan95.exe
    • Scan32.exe
    • Safeweb.exe
    • Regedit.exe
    • Rescue.exe
    • Rav7win.exe
    • Rav7.exe
    • Persfw.exe
    • Pcfwallicon.exe
    • Pccwin98.exe
    • Pavw.exe
    • Pavsched.exe
    • Pavcl.exe
    • Padmin.exe
    • Outpost.exe
    • Nvc95.exe
    • Nupgrade.exe
    • Normist.exe
    • Nmain.exe
    • Nisum.exe
    • Navwnt.exe
    • Navw32.exe
    • Navnt.exe
    • Navlu32.exe
    • Navapw32.exe
    • N32scanw.exe
    • Mpftray.exe
    • Moolive.exe
    • Luall.exe
    • Lookout.exe
    • Lockdown2000.exe
    • Jedi.exe
    • Iomon98.exe
    • Iface.exe
    • Icsuppnt.exe
    • Icsupp95.exe
    • Icmon.exe
    • Icloadnt.exe
    • Icload95.exe
    • Ibmavsp.exe
    • Ibmasn.exe
    • Iamserv.exe
    • Iamapp.exe
    • Frw.exe
    • Fprot.exe
    • Fp-Win.exe
    • Findviru.exe
    • f-Stopw.exe
    • f-Prot95.exe
    • f-Prot.exe
    • f-Agnt95.exe
    • Espwatch.exe
    • Esafe.exe
    • Ecengine.exe
    • Dvp95_0.exe
    • Dvp95.exe
    • Cleaner3.exe
    • Cleaner.exe
    • Claw95cf.exe
    • Claw95.exe
    • Cfinet32.exe
    • Cfinet.exe
    • Cfiaudit.exe
    • Cfiadmin.exe
    • Blackice.exe
    • Blackd.exe
    • Avwupd32.exe
    • Avwin95.exe
    • Avsched32.exe
    • Avpupd.exe
    • Avptc32.exe
    • Avpm.exe
    • Avpdos32.exe
    • Avpcc.exe
    • Avp32.exe
    • Avp.exe
    • Avnt.exe
    • Avkserv.exe
    • Avgctrl.exe
    • Ave32.exe
    • Avconsol.exe
    • Autodown.exe
    • Apvxdwin.exe
    • Anti-Trojan.exe
    • Ackwin32.exe
    • _Avpm.exe
    • _Avpcc.exe
    • _Avp32.exe

  9. Stop the Norton AntiVirus Auto-Protect Service.

  10. Remove the Trojan Defense Suite.

  11. Delete all the files from the C:\SAFEWEB\ folder.

  12. If Microsoft IIS is installed, the worm will create a batch file, Anadf.txt.bat, which is intended to do the following:
    • Overwrite the following files with this content:

      Anacon G0t ya! By Melhacker -dA r34L #4(k3R!

    • Delete all the .log files in the root folders of drives C and D.

  13. Download a file from a specified URL.

  14. The worm may perform some the following actions:
    1. Drop and run a reg file, ANa.REG, to:
      • Create the following registry keys:

      • Add the binary value:


        to the following registry keys:


        NOTE: This will open a share for drive C:\.

    2. Perform a Denial of Service (DoS) attack on the following IP addresses:

    3. Search for the following folders:
      • %ProgramFiles%\KMD\My Shared Folder
      • %ProgramFiles%\Kazaa\My Shared Folder
      • %ProgramFiles%\KaZaA Lite\My Shared Folder
      • %ProgramFiles%\Morpheus\My Shared Folder
      • %ProgramFiles%\Grokster\My Grokster
      • %ProgramFiles%\BearShare\Shared
      • %ProgramFiles%\Edonkey2000\Incoming
      • %ProgramFiles%\limewire\Shared

        NOTE: %ProgramFiles% is a variable. By default, this is C:\Program Files.

    4. If the worm finds any of the aforementioned folders, it will copy itself as:
      • The Lost Jungle.mpg.exe
      • The Matrix Reloaded Trailer.jpg.exe
      • Replacement Killer 2.avi.exe
      • Trailer DOOM III.exe
      • WinZip9Beta.exe
      • WhatIsGoingOn.exe
      • NokiaPolyPhonic.exe
      • TNT.exe
      • Dont Eat Pork SARS in there.exe
      • About SARS Solution.doc.exe
      • Uninstal.exe
      • WindowsSecurity Patch.exe
      • Hide Your Mount.exe
      • Patch - jdbgmgr.exe
      • Generate a Random PAssword.exe
      • OfficeXP.exe
      • Ripley Believe It Or Not.exe
      • Anacon The Great.exe
      • New Variant.exe
      • SMTP OCX.exe
      • DialUp.pif
      • Lost YourPassword.txt.exe
      • Hack In 5 Minute.exe
      • Get Lost.exe
      • Oh Yeah Babe.exe
      • Sucker.exe
      • Downloader.exe
      • HeavyMetal.mp3.exe
      • JackAndGinnie.exe
      • RosalindaAyamor
      • fxanacon.com
      • GetMorePower.exe
      • Hacker HandBook.exe
      • Dincracker eZine.exe
      • La Intrusa.exe
      • Porta.exe

    5. Delete all the files in the root folder.

    6. Format the D: drive.

  15. Wait for the commands from the worm's creator to perform the following actions:
    • List/Delete/Execute files
    • List/Kill processes
    • Change display settings
    • Send keys
    • Play AVI and/or WAV files
    • Restart computer
    • Terminates RAS connections
    • Display message
    • Open/Close CD tray
    • Enable/Disable double-click
    • Open/Close clipboard
    • Remove itself
    • Start a keylogger
    • Change wallpaper
    • Hide/Show the system taskbar
    • Swap mouse button
    • Enable/Disable the system hotkey (Ctrl+Alt+Delete)

  16. Adds multiple shortcuts to copies of itself to the Windows Startup menu. Filenames are randomly generated, of the form <random>.exe, where random consists of a name made up of hexadecimal digits. This means several copies of the worm may attempt to run on startup, causing considerable disruption and instability to an infected system.

  17. Uses MAPI to email itself to all the contacts in the Windows Address Book. The email has the following characteristics:

    Subject: (One of the following)
    Microsoft Windows LONGHORN XP
    Your XXX Password: ud78sd8df
    Alert! New Variant W32/Naco.F@mm has been detected!
    Small and Destructive
    You r a chichy boy, You r a chicky girl
    TecTV: New Anti Virus Software
    Crack for Nokia LogoManager 1.3
    Gotcha Baby!
    Seagate Baracuda 80GB for $???
    FoxNews Reporter: What
    Get Free SMTP Server at Click Here!
    Patch for Microsoft Windows XP 64bit
    Brittish Air Way will backcrupt
    Help Me plz?
    Less and More
    News: US Goverment try to make wars with Tehran.
    • Attachment:
    • Body
      Hello dear,

      I'm gonna missed you babe, hope we can see again!

      In Love,
      Rekcahlem ~<>~ Anacon


      Hi babe, Still missing me! I have send to you a special gift I made it my own. Just for you. Check it out the attachment.

      Your Love,


      Great to see you again babe! This is file you want las week. Please don't distribute it to other.



      Please do not eat pork! The SARS virus may come from the pig. So becareful. For more information check the attachment.
      Regard, WTO



      You may not see the message because the message has been convert to the attachment. Please open an attachment to see the message.


    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: Neal Hindocha

    Discovered: June 12, 2003
    Updated: February 13, 2007 12:02:35 PM
    Also Known As: W32/Anacon-D [Sophos], I-Worm.Nocana.f [KAV], W32/Naco.f@MM [McAfee], W32/Naco.F@mm [Frisk], PE_NACO.F [Trend], Win32.Naco.E [CA]
    Type: Worm
    Systems Affected: Microsoft IIS, Windows

    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. Reverse the changes that the worm made to the registry, and then restart the computer.
    3. Update the virus definitions.
    4. Run a full system scan, delete all the files detected as W32.Naco.C@mm, and replace them if necessary.
    5. Reverse the changes that the worm made to IIS.
    For specific details on each of these steps, read the following instructions.

    1. Disabling System Restore in Windows Me/XP
    Users of Windows Me and Windows XP should 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 have backed 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 to restore an infected file on your computer even after you have cleaned the infected files from all the other locations.

    Also, in some cases, online scanners may detect a threat in the System Restore folder even if you scanned your computer with an antivirus program and did not find any infected files.

    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. Reversing the changes in the registry, restarting the computer

    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:


    4. In the right pane, delete the value:


    5. Navigate to the key:


    6. In the right pane, delete the value:


    7. Navigate to the key:


    8. In the right pane, delete the value:


    9. Navigate to the key:


    10. In the right pane, delete the values:


    11. Delete the following keys:

    12. Exit the Registry Editor.

    13. Restart the computer.

    3. 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.

    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 W32.Naco.C@mm, click Delete.
    4. If required, replace the files from a known, clean backup copy.

    5. Reversing the changes made to IIS
    1. Navigate to the \Inetpub\wwwroot folder.
    2. Restore the following files:
      • "default.asp"
      • "index.htm"
      • "default.htm"
      • "index.html"
      • "default.html"
      • "index.asp"

    Writeup By: Neal Hindocha