Dialer.Switchdialer.B

SUMMARY

Behavior

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

Symptoms

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

Transmission

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

Protection

• Virus Definitions (LiveUpdate™ Weekly) March 10, 2004
• Virus Definitions (Intelligent Updater) March 8, 2004

TECHNICAL DETAILS

When Dialer.SwitchDialer.B is executed, it performs the following actions:

1. Copies itself to the %System% folder.
   
   

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   Note: %System% is a variable. The dialer locates the System folder and copies itself to that location. By default, this is C:WindowsSystem (Windows 95/98/Me), C:WinntSystem32 (Windows NT/2000), or C:WindowsSystem32 (Windows XP).

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2. Adds the subkeys:
   
   • .cxq
   • .mxq
   • cxqfile
     
     to the registry key:
     
     HKEY_CLASSES_ROOT
     
     
3. Adds the following resgistry subkeys:
   
   • HKEY_LOCAL_MACHINESOFTWAREStartportal
   • HKEY_LOCAL_MACHINESOFTWARESwitchDialer
   • HKEY_LOCAL_MACHINESOFTWAREMicrosoftActive SetupInstalled Components{5CBF8C22-E9A6-11D7-90FE-000AE4012DB4}
     
     
4. Adds the value:
   
   "Diskstart" = "%System%<filename>"
   
   to the registry subkey:
   
   HKEY_LOCAL_MACHINESOFTWAREMicrosoftWindowsCurrentVersionRun
   
   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_MACHINESOFTWAREMicrosoftActive SetupClsidFeature
   
   
6. Adds the values:
   
   "TYPE34" = "application/x-callswitch"
   "application/x-callswitch" = "%System%<filename>"
   
   to the registry subkey:
   
   HKEY_CURRENT_USERSoftwareNetscapeNetscape NavigatorViewers
   
   
7. Adds the value:
   
   "%System%<filename>" = "Yes"
   
   to the registry subkey:
   
   HKEY_CURRENT_USERSoftwareNetscapeNetscape NavigatorUser Trusted External Applications

REMOVAL

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

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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.

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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_CLASSES_ROOT
   
   
4. Delete the subkeys:
   
   • .cxq
   • .mxq
   • cxqfile
     
     
5. Navigate to the key:
   
   HKEY_LOCAL_MACHINESoftware
   
   
6. Delete the subkeys:
   
   • Startportal
   • SwitchDialer
     
     
7. Navigate to the key:
   
   HKEY_LOCAL_MACHINESoftwareMicrosoftActive SetupInstalled Components
   
   
8. Delete the subkey:
   
   {5CBF8C22-E9A6-11D7-90FE-000AE4012DB4}
   
   
9. Navigate to the key:
   
   HKEY_LOCAL_MACHINESoftwareMicrosoftWindowsCurrentVersionRun
   
   
10. In the right pane, delete the value:
    
    "Diskstart" = "%System%<filename>"
    
    
11. Navigate to the key:
    
    HKEY_LOCAL_MACHINESoftwareMicrosoftActive SetupClsidFeature
    
    
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_USERSOFTWARENetscapeNetscape NavigatorViewers
    
    
14. In the right pane, delete the value:
    
    • "TYPE34" = "application/x-callswitch"
    • "application/x-callswitch" = "%System%<filename>"
      
      
15. Navigate to the key:
    
    HKEY_CURRENT_USERSOFTWARENetscapeNetscape NavigatorUser 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.
   
   

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   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.

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