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24 June 2005
13 February 2007
Systems Affected:

VBS.Inker is a VBS script worm that attempts to perform malicious acts, including attempts at a mass-mailing.

Antivirus Protection Dates

  • Initial Rapid Release version 25 June 2005
  • Latest Rapid Release version 28 September 2010 revision 054
  • Initial Daily Certified version 25 June 2005
  • Latest Daily Certified version 28 September 2010 revision 036
  • Initial Weekly Certified release date 29 June 2005
Click here for a more detailed description of Rapid Release and Daily Certified virus definitions.

When VBS.Inker is executed, it performs the following actions:
  1. Creates some or all of the following files:

    • %Windir%\Ip.bat
    • C:\WINDOWS\Ipnuker.vbs
    • C:\mirc\Ipnuker.vbs
    • %Windir%\IpUserCreate.bat
    • C:\[RANDOM NUMBER].txt
    • %Windir%\IpUser.bat

      Note: %Windir% is a variable that refers to the Windows installation folder. By default, this is C:\Windows or C:\Winnt.

  2. Adds the values:

    "WindosXp" = "Wscript.exe [SCRIPT NAME]"
    "DisableKeyboard" = "Rundll32.exe Keyboard,Disable"
    "DisableMouse" = "Rundll32.exe Mouse,Disable"

    to the registry subkey:


    so that the threat runs every time Windows starts and attempts to disable the keyboard and mouse.

  3. Executes a command that swaps the mouse buttons.

  4. Deletes the folder C:\Program files\Norton AntiVirus, if present.

  5. Modifies the value:

    "NoDesktop" = "1"

    in the registry subkey:


    to hide the desktop.

  6. Sets the following registry entries:

    HKEY_CLASSES_ROOT\VBSFile\DefaultIcon\"DefaultIcon" = "shell32.dll,-298"
    HKEY_CLASSES_ROOT\txtfile\DefaultIcon\"DefaultIcon" = "shell32.dll,-16"
    KEY_CLASSES_ROOT\inifile\DefaultIcon\"DefaultIcon" = "shell32.dll,-16"
    HKEY_CLASSES_ROOT\mpegfile\DefaultIcon\"DefaultIcon" = "shell32.dll,-52"
    HKEY_CLASSES_ROOT\jpegfile\DefaultIcon\"DefaultIcon" = "shell32.dll,-52"
    HKEY_CLASSES_ROOT\mp3file\DefaultIcon\"DefaultIcon" = "shell32.dll,-512"
    HKEY_CLASSES_ROOT\inffile\DefaultIcon\"DefaultIcon" = "shell32.dll,-5"

    which resets the .vbs, .txt., .ini, .mpg, .jpg, .mp3 and .inf icons.

  7. Modifies the value:

    "(Default)" = "%System%\System32\WScript.exe"

    in the registry subkeys:


    to change how the following actions are executed:

    • edit
    • open
    • print

  8. Modifies the value:

    "(Default)" = "C:\WINDOWS\Ipnuker.vbs"

    in the registry subkey:


    so that worm runs when Windows Explorer starts.

  9. Modifies the value by adding one of the following:

    "RegisteredOwner" = "Ipnuker.Net"
    "RegisteredOwner" = "Ipnuker"

    in the registry subkey:


    to reset the registered owner.

  10. Modifies the value by adding one of the following:

    "Start_Page" = "c:\WINDOWS\Ipnuker.vbs"
    "Start_Page" = "[http://][REMOVED]"

    in the registry subkey:

    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Internet Explorer\Main

    to redirect the Internet Explorer home page.

  11. Attempts to spread via mIRC by creating a VBS file attachment. It does this by looking for the folders C:\Mirc, C:\Mirc32 and for the file, mirc.ini in those folders. If the file is found, the worm will either create or overwrite the script.ini file.

    Note: The worm never writes the vbs file to be sent.

  12. May modify autoexec.bat. to read:

    @echo off
    echo This Computer Was Made By [REMOVED]
    echo Copyrighted By [REMOVED] For Forever

  13. Searches files with the extensions .vbs, .bat, .txt, .vbe or .ini. If these file types are found, the worm overwrites the file with a copy of itself.

  14. Uses MAPI commands to send itself to all addresses in the Microsoft Outlook address book. The email has the following characteristics:

    • If the date is the 1st through the 14th of January, June or December:

      Subject: Important Windows Security Update
      Message: Open the attachment to begin the windows update. This update is very important to ensure your safety. Microsoft
      Attachment: Ipnuker.vbs

    • If the date is the 15th through the last day of January, June or December:

      Subject: Yo Wats Up There
      Message: Open the attached file to get to the pictures you wanted.
      Attachment: Ipnuker.vbs

  15. Creates a random network user name when one of the following batch files is executed:

    • %Windir%\IpUserCreate.bat
    • %Windir%\IpUser.bat


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.

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.
  4. Delete any values added to the registry.
  5. Reset the changed icons.
For specific details on each of these steps, read the following instructions.

1. To disable 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:
When you are completely finished with the removal procedure and are satisfied that the threat has been removed, 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. To update 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 Virus Definitions (LiveUpdate).
  • Downloading the definitions using the Intelligent Updater: The Intelligent Updater virus definitions are posted daily. 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 Virus Definitions (Intelligent Updater).

    The latest Intelligent Updater virus definitions can be obtained here: Intelligent Updater virus definitions. For detailed instructions read the document: How to update virus definition files using the Intelligent Updater.

3. To scan for and delete 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, click Delete.

Important: If you are unable to start your Symantec antivirus product or the product reports that it cannot delete a detected file, you may need to stop the risk from running in order to remove it. To do this, run the scan in Safe mode. For instructions, read the document, How to start the computer in Safe Mode . Once you have restarted in Safe mode, run the scan again.

After the files are deleted, restart the computer in Normal mode and proceed with the next section.

Warning messages may be displayed when the computer is restarted, since the threat may not be fully removed at this point. You can ignore these messages and click OK. These messages will not appear when the computer is restarted after the removal instructions have been fully completed. The messages displayed may be similar to the following:

Title: [File path]
Message body: Windows cannot find [file name]. Make sure you typed the name correctly, and then try again. To search for a file, click the Start button, and then click Search.

4. To delete the value from the registry
Important: 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 subkeys only. For instructions refer to the document: How to make a backup of the Windows registry.
  1. Click Start > Run.
  2. Type regedit
  3. Click OK.

    Note: If the registry editor fails to open the threat may have modified the registry to prevent access to the registry editor. Security Response has developed a tool to resolve this problem. Download and run this tool, and then continue with the removal.

  4. Navigate to the subkey:


  5. In the right pane, delete the values:

    "WindosXp" = "Wscript.exe [SCRIPT NAME]"
    "DisableKeyboard" = "Rundll32.exe Keyboard,Disable"
    "DisableMouse" = "Rundll32.exe Mouse,Disable"

  6. Navigate to the subkey:


  7. In the right pane, delete the value:

    "NoDesktop" = "1"

  8. Navigate to the subkeys:


  9. In the right pane, reset the following value:

    "(Default)" = "%System%\System32\WScript.exe"

    with the following value:

    "(Default)" = "%Windir%\notepad.exe "%1""

  10. Navigate to the subkeys:


  11. In the right pane, reset the following value:

    "(Default)" = "%System%\System32\WScript.exe"

    with the following value:

    "(Default)" = "%System%\system32\NOTEPAD.EXE /p %1"

  12. Navigate to the subkeys:


  13. In the right pane, reset the following value:

    "(Default)" = "%System%\System32\WScript.exe"

    with the following value:

    "(Default)" = "%System%\system32\notepad.exe /pt "%1" "%2" "%3" "%4""

  14. Navigate to the subkeys:


  15. In the right pane, reset the following value:

    "(Default)" = "%System%\System32\WScript.exe"

    with the following value:

    "(Default)" = "%System%\system32\rundll32.exe %System%\system32\shell32.dll,OpenAs_RunDLL %1"

  16. Navigate to the subkeys:


  17. In the right pane, delete the value:

    "(Default)" = "%SystemRoot%\System32\WScript.exe"

    Note: You may have to reset your Windows desktop theme via the Control Panel.

  18. Navigate to the subkey:


  19. In the right pane, reset the value:

    "(Default)" = "C:\WINDOWS\Ipnuker.vbs"

    with the following value:

    "(Default)" = "%SystemRoot%\Explorer.exe /e,/idlist,%I,%L"

  20. Navigate to the subkey:


  21. In the right pane, delete the values, if present:

    "RegisteredOwner" = "Ipnuker.Net"
    "RegisteredOwner" = "Ipnuker"

    and reset with the correct information.

  22. Navigate to the subkey:

    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Internet Explorer\Main

  23. In the right pane, delete the values, if present:

    "Start_Page" = "c:\WINDOWS\Ipnuker.vbs"
    "Start_Page" = "[http://][REMOVED]"

  24. Exit the Registry Editor.

5. To reset the modified icons
You can reset changed icons by doing the following:
  1. Click on My Computer
  2. Click on Tools on the Menu bar.
  3. Select Folder Options on the drop down menu.
  4. Click on the File Types tab.
  5. Select the application and press Advanced.
  6. You will then have the option to change Icons.

Writeup By: Maryl Magee