Dialer.Comsoft

SUMMARY

Behavior

Dialer.Comsoft is a dialer program that can be used to access various Web sites by dialing a high-cost phone number using the modem. The sites that can be accessed are mostly pornographic.

Symptoms

• New Icon on Desktop
  
• Files are detected as Dialer.Comsoft

Transmission

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

Protection

• Virus Definitions (LiveUpdate™ Weekly) September 24, 2003
• Virus Definitions (Intelligent Updater) September 24, 2003

TECHNICAL DETAILS

When Dailer.Comsoft is executed, it does the following:

1. Creates the folder, C:Program Filescomsoftdialers, into which it drops a copy of itself.
   
   
2. Adds a value corresponding to the name of the dropped executable to the registry key:
   
   HKEY_LOCAL_MACHINESOFTWAREMicrosoftWindowsCurrentVersionRun
   
   so that the Dialer program runs when you start Windows.
   
   The value consists of the name and full path to the executable, followed by /noconnect.
   
   
3. Creates a shotcut to the dialer on the Windows Desktop.
   
   
4. Creates the following registry keys for storing dialer settings:
   
   HKEY_CURRENT_USERSoftwareComsoft
   HKEY_CURRENT_USERSoftwareComsoftDialers
   HKEY_CURRENT_USERSoftwareComsoftDialers[customname]
   

REMOVAL

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Note: Removing this adware component from the system will likely cause the program that installed it to not function as intended. The uninstaller generally identifies the programs that will not work after uninstallation.

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1. Update the virus definitions.
2. Close modem connections.
3. Uninstall the dialer using the Add/Remove Programs utility.
4. Run a full system scan and delete all the files detected as Dialer.Comsoft.
5. Delete the value that was added to the registry.
   

For specific details on each of these steps, read the following instructions.

1. 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.
  

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. Uninstalling the Dialer

1. Do one of the following:
   • On the Windows 98 taskbar:
     1. Click Start > Settings > Control Panel.
     2. In the Control Panel window, double-click Add/Remove Programs.
        
        
   • On the Windows Me taskbar:
     1. Click Start > Settings > Control Panel.
     2. In the Control Panel window, double-click Add/Remove Programs.
        If you do not see the Add/Remove Programs icon, click "...view all Control Panel options."
        
        
   • On the Windows 2000 taskbar:
     By default, Windows 2000 is set up the same as Windows 98. In that case, follow the instructions for Windows 98. Otherwise, click Start, point to Settings, point to Control Panel, and then click Add/Remove Programs.
     
     
   • On the Windows XP taskbar:
     1. Click Start > Control Panel.
     2. In the Control Panel window, double-click Add or Remove Programs.
        
        
2. Click the name of the dialer program, which can vary. If you do not know the name, skip to section 3.
   
   

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   Note: You may need to use the scroll bar to view the whole list.

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3. Click Add/Remove, Change/Remove, or Remove (this varies with the operating system). Follow the prompts.

4. Scanning for and deleting the infected 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 infected with Dialer.Comsoft, click Delete.

5. 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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Note: This is done to make sure that all the keys are removed. The keys may not be there if the uninstaller removed them.

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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_LOCAL_MACHINESOFTWAREMicrosoftWindowsCurrentVersionRun
   
   
4. In the right pane, delete the value corresponding to the dialer.
   
   
5. Exit the Registry Editor.