Trojan.Vavico - 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. Restart the computer in Safe mode or VGA mode.
3. Editing the Win.ini and System.ini files (Windows 95/98/Me).
4. Reverse the changes made to the registry.
5. Restore Norton AntiVirus
6. Update the virus definitions.
7. Run a full system scan and delete all the files detected as Trojan.Vavico.

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

1. 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"

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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.

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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. Restarting 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, users, restart the computer in Safe mode. For instructions, read the document, "How to start the computer in Safe Mode."
• For Windows 2000, or XP users, restart the computer in Safe mode with command prompt. For instructions, read the document, "How to start the computer in Safe Mode."
• For Windows NT 4 users, restart the computer in VGA mode with command prompt.
  
  

3. Editing the Win.ini and System.ini files (Windows 95/98/Me only)
If you are running Windows 95/98/Me, follow these steps:

1. The function you perform depends on your operating system:
   • Windows 95/98: Go to step B.
   • Windows Me: If you are running Windows Me, the Windows Me file-protection process may have made a backup copy of the Win.ini and System.ini files that you need to edit. If this backup copy exists, 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 delete it. The Win.ini file will be regenerated when you save your changes to it in step F.
     4. In the right pane, select the System.ini file and delete it. The System.ini file will be regenerated when you save your changes to it in step N.
        
        
2. Click Start, and then click Run.
   
   
3. Type the following, and then click OK.
   
   edit %windir%\win.ini
   
   (The MS-DOS Editor opens.)
   
   

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   Note: If Windows is installed in a different location, make the appropriate path substitution.

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4. In the [windows] section of the file, look for a line similar to:
   
   load=Exploder.exe
   
   
5. If this line exists, delete everything to the right of load=
   
   
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 %windir%\system.ini
   
   (The MS-DOS Editor opens.)
   
   

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   Note: If Windows is installed in a different location, make the appropriate path substitution.

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10. In the [boot] section of the file, look for a line similar to:
    
    shell=Explorer.exe Run.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. In the [boot] section of the file, look for a line similar to:
    
    SCRNSAVE.EXE=%System%\3d_Papa_Buzzie.Scr
    
    
13. If this line exists, delete it.
    
    
14. Click File, and then click Save.
    
    
15. Click File, and then click Exit.
    
    
16. Restart the computer in safe mode.

4. Reversing the changes made to 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. If you are running Windows 95/98/Me, Click Start, and then click Run. (The Run dialog box appears.)
   
   And type regedit in the Run dialog box.
   
   Then click OK. (The Registry Editor opens.)
   
   
2. If you are running Windows NT/2000/XP, Type regedit and push the Enter key on the command prompt.
   
   
3. Navigate to the key:
   
   HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Run
   
   
4. In the right pane, delete the following values:
   
   • "Kernel32" = "Krnl836.exe"
   • "Terminal Services" = "term32.exe"
   • "Norton AntiVirus" = "C:\Program Files\Norton AntiVirus\NAVW32.exe"
     
     
5. Navigate to the key:
   
   HKEY_CURRENT_USER\Control Panel\Desktop
   
   
6. In the right pane, delete the value:
   
   "SCRNSAVE.EXE" = "C:\WINDOWS\System32\3d_Papa_Buzzie.Scr"
   
   
7. Navigate to the key:
   
   HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer
   
   
8. In the right pane, delete the value:
   
   "Varianico83" = "By Buggie..."
   
   
9. If you are running Windows 95/98/Me, navigate to the key:
   
   HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\RunServices
   
   
10. In the right pane, delete the value:
    
    "PC-health"="%Windir%\PC-health\PCguard.exe"
    
    
11. If you are running Windows 95/98/Me, go to step s.
    
    
12. Navigate to the key:
    
    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Command Processor
    
    
13. In the right pane, delete the value:
    
    "AutoRun" = "echo off|Copy C:\WINDOWS\Config\driver.idf C:\Mario.exe|Cls|echo. ___vicious'83 (...by Buggie_haeza-tsu)"
    
    
14. Navigate to the key:
    
    HKEY_CURRENT_USER\Software\Microsoft\Windows NT\CurrentVersion\Windows
    
    
15. In the right pane, delete the value:
    
    "Load" = "Exploder.exe"
    
    
16. Navigate to the key:
    
    KEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\CurrentVersion\Winlogon
    
    
17. Modify the "Shell" value to the following:
    
    "Shell" = "explorer.exe"
    
    
18. Exit the Registry Editor.
    
    
19. 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."

5. Restoring Norton AntiVirus (if applicable)
If you installed Norton AntiVirus to the default folder, C:\Program Files\Norton AntiVirus, you may have to re-install this program. For more information on completing this process, read the document, "Restoring Norton AntiVirus after it is infected by a virus."

6. 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.

7. 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 Trojan.Vavico, click Delete.

Technical Details