W32.Bambo - Removal

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

NOTE: These instructions assume that the computer is already infected with W32.Bambo and that the Trojan has executed and is running. If your Symantec antivirus product detects W32.Bambo when the Trojan attempts to execute, this indicates that W32.Bambo has been caught and prevented from running. In this situation, delete W32.Bambo, and to be secure, follow the instructions in Sections 5 and 6 below:

1. Restart the computer in Safe mode or VGA mode.
2. Delete the values that were added to the registry.
3. Delete the lines that were added to the Win.ini and System.ini files (Windows 95/98/Me).
4. Disable System Restore (Windows Me/XP).
5. Update the virus definitions.
6. Run a full system scan and delete all the files detected as W32.Bambo.

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

1. Restarting 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, refer to the document, "How to start the computer in Safe Mode."
• For Windows NT 4 users, restart the computer in VGA mode.

2. Deleting the value from 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:
   
   "load32"="%System%\load32.exe"
   
   
5. If you are running Windows 95/98/Me, navigate to the key:
   
   HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\
   RunServices
   
   
6. In the right pane, delete the value:
   
   "ZoneAlarm 2.99"="%Windows%\Sysdrv.exe"
   
   
7. Exit the Registry Editor.
8. Follow the instructions for your operating system:
   • Windows 95/98/Me: Proceed to Section 3.
   • Windows NT/2000/XP:
     1. Shut down the computer, turn off the power, and wait 30 seconds.
     2. Restart the computer in Normal mode. When the computer restarts, proceed to section 5.

3. Deleting the lines that were added to the Win.ini and System.ini files
If you are running Windows 95/98/Me, follow these steps:

1. The function you perform depends on your operating system:
   • Windows 95/98: Proceed to step b.
   • Windows Me: If you are running Windows Me, the Windows Me file-protection process may have made backup copies of the Win.ini and System.ini files that you need to edit. If these copies exist, it will be in the C:\Windows\Recent folder. Symantec recommends that you delete these files before continuing with the steps in this section. To do this:
     1. Start Windows Explorer.
     2. Browse to and select the C:\Windows\Recent folder.
     3. In the right pane, select the Win.ini file and the System.ini files, and then delete them. The files will be regenerated when you save your changes to them in the following step.
        
        
2. Click Start, and then click Run.
3. Type the following, and then click OK.
   
   edit c:\windows\win.ini
   
   (The MS-DOS Editor opens.)
   
   NOTE: If Windows is installed in a different location, make the appropriate path substitution.
   
   
4. Look for a line similar to:
   
   run=C:\Windows\Dllreg.exe
   
   
5. If this line exists, delete it.
6. Click File, and then click Save.
7. Click File, and then click Exit.
8. Click Start, and then click Run.
9. Type the following, and then click OK.
   
   edit c:\windows\system.ini
   
   
10. Look for the line:
    
    shell=explorer.exe C:\WINDOWS\SYSTEM\vxdmgr32.exe
    
    
11. If this line exists, delete everything to the right of Explorer.exe.
    
    When you are done, it should look like:
    
    shell=explorer.exe
    
    
12. Click File, and then click Save.
13. Click File, and then click Exit.
14. Shut down the computer, turn off the power, and wait 30 seconds.
15. Restart the computer in Normal mode. When the computer restarts, proceed to Section 4.

4. Disabling 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"

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.

5. 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.

6. 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.Bambo, click Delete.

Technical Details