VBS.Bootconf

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Discovered: November 03, 2003
Updated: February 13, 2007 12:13:18 PM
Type: Trojan Horse
Systems Affected: Windows


VBS.Bootconf is a Trojan horse that modifies the TCP/IP settings to point to a different address. It also changes the Internet Explorer home page and search page to connect to www.royalsearch.net.

VBS.Bootconf is written in Visual Basic Script.

Antivirus Protection Dates

  • Initial Rapid Release version November 03, 2003
  • Latest Rapid Release version September 28, 2010 revision 054
  • Initial Daily Certified version November 03, 2003
  • Latest Daily Certified version September 28, 2010 revision 036
  • Initial Weekly Certified release date November 05, 2003

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

Writeup By: Hiroshi Shinotsuka

Discovered: November 03, 2003
Updated: February 13, 2007 12:13:18 PM
Type: Trojan Horse
Systems Affected: Windows


When the VBS.Bootconf is executed, it performs the following actions:

  1. Adds the following entries to the HOSTS file:

    <IP address> auto.search.msn.com
    <IP address> search.msn.com
    <IP address>  msn.com
    <IP address> www.msn.com

    which redirects the above URLs to a predetermined IP address.

  2. Adds or modifies the values:
    • "Start Page" = "www.royalsearch.net"
    • "Search Page" = "www.royalsearch.net/search.html"
    • "Search Bar" = "www.royalsearch.net/search.html"
    • "Use Search Asst" = "no"

      in the registry key:

      HKEY_LOCAL_MACHINE\Software\Microsoft\Internet Explorer\Main

  3. Adds the value:

    "SearchURL" = "www.royalsearch.net/search.php?q=%s"

    in the registry key:

    HKEY_LOCAL_MACHINE\Software\Microsoft\Internet Explorer

  4. Modifies the values:
    • "SearchAssistant" = "www.royalsearch.net/search.html"
    • "CustomizeSearch" = "www.royalsearch.net/search.html"

      in the registry key:

      HKEY_LOCAL_MACHINE\Software\Microsoft\Internet Explorer\Search

  5. Modifies the values:
    • "Start Page" = "www.royalsearch.net"
    • "Search Page" = "www.royalsearch.net/search.html"
    • "Default_Page_URL" = "www.royalsearch.net"
    • "Default_Search_URL" = "www.royalsearch.net/search.html"

      in the registry key:

      HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main

  6. Modifies the values:
    • "SearchAssistant" = "www.royalsearch.net/search.html"
    • "CustomizeSearch" = "www.royalsearch.net/search.html"
    • "Default_Search_URL" = "www.royalsearch.net/search.html"

      in the registry key:

      HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Search


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: Hiroshi Shinotsuka

Discovered: November 03, 2003
Updated: February 13, 2007 12:13:18 PM
Type: Trojan Horse
Systems Affected: Windows



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

  1. Update the definitions.
  2. Restart the computer in Safe mode or VGA mode.
  3. Run a full system scan and delete all the files detected as VBS.Bootconf.
  4. Delete the value that was added to the registry.
  5. Restore the Internet Explorer settings.
  6. Reverse the changes that were made to the Hosts file.
For specific details on each of these steps, read the following instructions.

1. Updating the definitions
To obtain the most recent definitions, start your Symantec program and run LiveUpdate.


2. 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.

3. Scanning for and deleting the files
  1. Start Norton AntiVirus and make sure that it is configured to scan all the files. For more information, read the document, "How to configure Norton AntiVirus to scan all files."
  2. Run a full system scan.
  3. If any files are detected as VBS.Bootconf, click Delete.

4. 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

    Then click OK. (The Registry Editor opens.)

  3. Navigate to the key:

    HKEY_LOCAL_MACHINE\Software\Microsoft\Internet Explorer\Main

  4. In the right pane, delete the values:
    • "Start Page" = "www.royalsearch.net"
    • "Search Page" = "www.royalsearch.net/search.html"
    • "Search Bar" = "www.royalsearch.net/search.html"
    • "Use Search Asst" = "no"

  5. Navigate to the key:

    HKEY_LOCAL_MACHINE\Software\Microsoft\Internet Explorer

  6. In the right pane, delete the values:

    "SearchURL" = "www.royalsearch.net/search.php?q=%s"

  7. Navigate to the key:

    HKEY_LOCAL_MACHINE\Software\Microsoft\Internet Explorer\Search

  8. In the right pane, delete the values:
    • "SearchAssistant" = "www.royalsearch.net/search.html"
    • "CustomizeSearch" = "www.royalsearch.net/search.html"

  9. Navigate to the key:

    HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main

  10. In the right pane, delete the values:
    • "Start Page" = "www.royalsearch.net"
    • "Search Page" = "www.royalsearch.net/search.html"
    • "Default_Page_URL" = "www.royalsearch.net"
    • "Default_Search_URL" = "www.royalsearch.net/search.html"

  11. Navigate to the key:

    HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Search

  12. In the right pane, delete the values:
    • "SearchAssistant" = "www.royalsearch.net/search.html"
    • "CustomizeSearch" = "www.royalsearch.net/search.html"
    • "Default_Search_URL" = "www.royalsearch.net/search.html"

  13. Exit the Registry Editor.

5. Restoring the Internet Explorer settings
Some of the changes that the Trojan makes to the registry will modify some Internet Explorer settings. One of the settings it changes is to the home page.

To reset the home page:
  1. Start Microsoft Internet Explorer.
  2. Connect to the Internet and go to the page that you want to set as your home page.
  3. Click Tools, and then click Internet Options.
  4. In the Home page section of the General tab, click Use Current, and then click OK.

If you notice any other problems when using Internet Explorer, change these settings within the program. See your Internet Explorer documentation for instructions.


6. Reversing the changes made to the Hosts file

Note: The location of the Hosts file may vary and some computers may not have this file. For example, if the file exists in Windows 98, it will usually be in C:\Windows, and it is located in the C:\WINNT\system32\drivers\etc folder in Windows 2000. There may also be multiple copies of this file in different locations.

Follow the instructions for your operating system:
  • Windows 95/98/Me/NT/2000
    1. Click Start, point to Find or Search, and then click Files or Folders.
    2. Make sure that "Look in" is set to (C:) and that "Include subfolders" is checked.
    3. In the "Named" or "Search for..." box, type:

      hosts

    4. Click Find Now or Search Now.
    5. For each one that you find, right-click it, and then click "Open With."
    6. Deselect the "Always use this program to open this program" check box.
    7. Scroll through the list of programs and double-click Notepad.
    8. Look for the following lines and delete them, if found:

      <IP address> auto.search.msn.com
      <IP address> search.msn.com
      <IP address> msn.com
      <IP address> www.msn.com
    9. Close Notepad and save your changes when prompted.

  • Windows XP
    1. Click Start, and then click Search.
    2. Click All files and folders.
    3. In the "All or part of the file name" box, type:

      hosts

    4. Verify that "Look in" is set to "Local Hard Drives" or to (C:).
    5. Click "More advanced options."
    6. Check "Search system folders."
    7. Check "Search subfolders."
    8. Click Search.
    9. Click Find Now or Search Now.
    10. For each one that you find, right-click it, and then click "Open With."
    11. Deselect the "Always use this program to open this program" check box.
    12. Scroll through the list of programs and double-click Notepad.
    13. Look for the following lines and delete them, if found:

      <IP address> auto.search.msn.com
      <IP address> search.msn.com
      <IP address> msn.com
      <IP address> www.msn.com

    14. Close Notepad and save your changes when prompted.


Writeup By: Hiroshi Shinotsuka