W32.Darby.B - Removal

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. Use the Security Response "Tool to reset shell\open\command registry keys."
3. Update the virus definitions.
4. Restart the computer in Safe mode or VGA mode.
5. Run a full system scan and delete all the files detected as W32.Darby.B.
6. Re-enable registry access.
7. Reverse the changes made to the registry.
8. Edit the Win.ini and Autoexec.bat files
   

For 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:

• "How to disable or enable Windows Me System Restore"
• "How to turn off or turn on Windows XP System Restore"

Note: When you are completely finished with the removal procedure and are satisfied that the threat has been removed, re-enable 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 use the Security Response "Tool to reset shell\open\command registry keys."

W32.Darby.B makes changes to the Windows registry that may prevent you from running the registry editor. Security Response has developed a tool to reset these values to the default settings.

This tool is the easiest way to fix this. Once you have run the tool, return to this page and continue with the removal.

If you cannot obtain the tool, refer to the "Additional Information" section for information on manually reversing the changes.
3. 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 the 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 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.

4. To restart 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.
  

5. 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.
   • For Norton AntiVirus consumer products: Read the document, "How to configure Norton AntiVirus to scan all files."
   • For Symantec AntiVirus Enterprise products: Read the document, "How to verify that a Symantec Corporate antivirus product is set to scan all files."
2. Run a full system scan.
3. If any files are detected as infected with W32.Darby.B, click Delete.

6. To re-enable registry access

If registry access has been disabled, do the following:

1. Click Start > Run.
2. Type:
   
   Notepad
   
   and then click OK.
   
   
3. Type, or copy and paste, the following text into the text file:
   
   REGEDIT4
   [HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\System]
   "DisableRegistryTools"=dword:00000000
   [HKEY_CURRENT_USER\Software\Microsoft\WindowsNT\CurrentVersion\Policies\System]
   "DisableRegistryTools"=dword:00000000
   
   
4. Save the file as C:\Repair.reg.
   
   
5. Click Start > Run.
   
   
6. Type:
   
   regedit -s C:\repair.reg
   
   and then click OK.
   

7. To reverse the changes made to 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 keys only. Read the document, "How to make a backup of the Windows registry," for instructions.

1. Click Start > Run.
2. Type regedit
   
   Then click OK.
   
   
3. Navigate to the key:
   
   HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
   HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\WindowsNT\CurrentVersion\Run
   
   
4. In the right pane, delete the value:
   
   "[random worm filename]" = "%System%\[random worm filename]"
   
   
5. Exit the Registry Editor.
   
   
6. Restart the computer in Normal mode. For instructions, read the section on returning to Normal mode in the document, "How to start the computer in Safe Mode."

8. To edit the Win.ini and Autoexec.bat files
If you are running Windows 95/98/Me, follow these steps:

1. Click Start > Run.
2. Type the following:
   
   edit c:\windows\win.ini
   
   and then click OK.
   
   (The MS-DOS Editor opens.)
   
   NOTE: If Windows is installed in a different location, make the appropriate path substitution.
   
   
3. In the [windows] section of the file, look for a line similar to:
   
   shell=Explorer.exe %System%\[random worm filename]
   
   
4. If this line exists, delete everything to the right of run=
   
   
5. Click File > Save.
   
   
6. Click File > Exit.
   
   
7. Click Start > Run.
   
   
8. Type the following:
   
   edit c:\autoexec.bat
   
   and then click OK.
   
   NOTE: If Windows is installed in a different location, make the appropriate path substitution.
   
   
9. Look for a line similar to:
   
   @win %System%\[random worm filename]
   
   
10. If this line exists, delete it.
    
    
11. Click File > Save.
12. Click File > Exit.

Technical Details