W32.Kwbot.E.Worm - Removal

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

1. Update the virus definitions.
2. Do one of the following:
   • Windows 95/98/Me: Restart the computer in Safe mode.
   • Windows NT/2000/XP: End the Trojan process.
3. Run a full system scan and delete all the files detected as W32.Kwbot.E.Worm.
4. Reverse the changes that the worm made to the registry.
   

For 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 here. For detailed instructions on how to download and install the Intelligent Updater virus definitions from the Symantec Security Response Web site, click here.

2. Restarting the computer in Safe mode or ending the Trojan process

Windows 95/98/Me
Restart the computer in Safe mode. All the Windows 32-bit operating systems, except for Windows NT, can be restarted in Safe mode. For instructions on how to do this, read the document, "How to start the computer in Safe Mode."

Windows NT/2000/XP
To end the Trojan process:
1. Press Ctrl+Alt+Delete once.
2. Click Task Manager.
3. Click the Processes tab.
4. Double-click the Image Name column header to alphabetically sort the processes.
5. Scroll through the list and look for Dllmem32.exe.
6. If you find the file, click it, and then click End Process.
7. Exit the Task Manager.
   

3. Scanning for and deleting 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.Kwbot.E.Worm, click Delete.

4. Reversing the changes made to the registry

CAUTION: 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\Windows\CurrentVersion\Run
   
4. In the right pane, delete the value:
   
   DLL32    dllmem32.exe
   
5. Navigate to the key:
   
   HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\
   RunServices
   
6. In the right pane, delete the value:
   
   DLL32    dllmem32.exe
   
7. Navigate to the key:
   
   HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\
   RunOnce
   
8. In the right pane, delete the value:
   
   DLL32    dllmem32.exe
   
9. Navigate to the key:
   
   HKEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\CurrentVersion\Winlogon
   
   NOTE: This key does not exist on all the systems. If you do not find it, proceed to the next step.
   
10. In the right pane, double-click Shell.
    
11. Change the text in the Value data box so that it only reads: Explorer.exe.
    
12. Navigate to each of the keys:
    
    HKEY_CURRENT_USER\Software\Kazaa\LocalContent
    HKEY_CURRENT_USER\Software\iMesh\Client\LocalContent
    
13. In the right pane, delete any values that refer to the %Windir%\CTemp32 folder. For example:
    
    Dir? 012345:%windows%\CTemp32
    
    NOTE: "?" in this value represents a number that the worm has chosen.
    
14. Exit the Registry Editor.

Technical Details