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13 February 2007
Risk Impact:
File Names:
Systems Affected:


Dialer.SwitchDialer.B is a dialer program that can be used to access online content by dialing high-cost numbers using a modem.


Your Symantec antivirus program detects the files as Dialer.SwitchDialer.B.


The most common installation method of this dialer is through various Web sites, mainly pornographic in nature.

Antivirus Protection Dates

  • Initial Rapid Release version 02 October 2014 revision 022
  • Latest Rapid Release version 07 May 2019 revision 006
  • Initial Daily Certified version 08 March 2004
  • Latest Daily Certified version 07 May 2019 revision 008
  • Initial Weekly Certified release date 10 March 2004
Click here for a more detailed description of Rapid Release and Daily Certified virus definitions.

When Dialer.SwitchDialer.B is executed, it performs the following actions:
  1. Copies itself to the %System% folder.

    Note: %System% is a variable. The dialer 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).

  2. Adds the subkeys:
    • .cxq
    • .mxq
    • cxqfile

      to the registry key:


  3. Adds the following resgistry subkeys:
    • HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Active Setup\Installed Components\{5CBF8C22-E9A6-11D7-90FE-000AE4012DB4}

  4. Adds the value:

    "Diskstart" = "%System%\<filename>"

    to the registry subkey:


    so that the dialer runs when you start Windows.

  5. Adds the value:

    "{5CBF8C22-E9A6-11D7-90FE-000AE4012DB4}" = "{5CBF8C22-E9A6-11D7-90FE-000AE4012DB4}!1,0,0,2"

    to the registry subkey:

    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Active Setup\ClsidFeature

  6. Adds the values:

    "TYPE34" = "application/x-callswitch"
    "application/x-callswitch" = "%System%\<filename>"

    to the registry subkey:

    HKEY_CURRENT_USER\Software\Netscape\Netscape Navigator\Viewers

  7. Adds the value:

    "%System%\<filename>" = "Yes"

    to the registry subkey:

    HKEY_CURRENT_USER\Software\Netscape\Netscape Navigator\User Trusted External Applications

The following instructions pertain to all Symantec antivirus products that support Security Risk detection.
  1. Update the definitions.
  2. Close modem connections
  3. Delete the value that was added to the registry.
  4. Run a full system scan and delete all the files detected as Dialer.Switchdialer.B.
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. To close modem connections
This risk uses available modems to create an Internet connection, sometimes without any visible signs. In order to successfully remove this threat, ensure that all modem-based Internet connections are disconnected before proceeding. For instructions on how to do this, consult the appropriate Internet service provider, computer manufacturer, or operating system documentation.

3. 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:


  4. Delete the subkeys:
    • .cxq
    • .mxq
    • cxqfile

  5. Navigate to the key:


  6. Delete the subkeys:
    • Startportal
    • SwitchDialer

  7. Navigate to the key:

    HKEY_LOCAL_MACHINE\Software\Microsoft\Active Setup\Installed Components

  8. Delete the subkey:


  9. Navigate to the key:


  10. In the right pane, delete the value:

    "Diskstart" = "%System%\<filename>"

  11. Navigate to the key:

    HKEY_LOCAL_MACHINE\Software\Microsoft\Active Setup\ClsidFeature

  12. In the right pane, delete the value:

    "{5CBF8C22-E9A6-11D7-90FE-000AE4012DB4}" = "{5CBF8C22-E9A6-11D7-90FE-000AE4012DB4}!1,0,0,2"

  13. Navigate to the key:

    HKEY_CURRENT_USER\SOFTWARE\Netscape\Netscape Navigator\Viewers

  14. In the right pane, delete the value:
    • "TYPE34" = "application/x-callswitch"
    • "application/x-callswitch" = "%System%\<filename>"

  15. Navigate to the key:

    HKEY_CURRENT_USER\SOFTWARE\Netscape\Netscape Navigator\User Trusted External Applications

  16. In the right pane, delete the value:

    "%System%\<filename>" = "Yes"

  17. Exit the Registry Editor.

  18. Restart the computer.

4. Scanning for and deleting the files
  1. Start your Symantec antivirus program, and then run a full system scan.
  2. If any files are detected as Dialer.Switchdialer.B, click Delete.

    Note: If your Symantec antivirus product reports that it cannot delete a detected file, write down the path and file name. Then use Windows Explorer to locate and delete the file.