W32.Nopir.C - 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. Update the virus definitions.
3. Run a full system scan and delete all the files detected.
4. Delete any values added to the registry.
5. Restore the Windows security center.
   

For specific 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, reenable 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 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 document: 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 document: Virus Definitions (Intelligent Updater).
  
  The latest Intelligent Updater virus definitions can be obtained here: Intelligent Updater virus definitions. For detailed instructions read the document: How to update virus definition files using the Intelligent Updater.

3. 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, click Delete.

Important: If your Symantec antivirus product reports that it cannot delete a detected file, Windows may be using the file. To fix this, run the scan in Safe mode. For instructions, read the document: How to start the computer in Safe Mode. Once you have restarted in Safe mode, run the scan again.

After the files are deleted, restart the computer in Normal mode and proceed with the next section.

Warning messages may be displayed when the computer is restarted, since the threat may not be fully removed at this point. You can ignore these messages and click OK. These messages will not appear when the computer is restarted after the removal instructions have been fully completed. The messages displayed may be similar to the following:

Title: [File path]
Message body: Windows cannot find [file name]. Make sure you typed the name correctly, and then try again. To search for a file, click the Start button, and then click Search.


4. To delete the value from 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 subkeys only. For instructions refer to the document: How to make a backup of the Windows registry.

1. Click Start > Run.
2. Type regedit
3. Click OK.
   
   Note: If the registry editor fails to open the threat may have modified the registry to prevent access to the registry editor. Security Response has developed a tool to resolve this problem. Download and run this tool, and then continue with the removal.
   
   
4. Navigate to the subkey:
   
   HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
   
   
5. In the right pane, delete the values:
   
   "sysmem" = "%ProgramFiles%\system prot\mmsete.exe"
   "memory" = "%ProgramFiles%\Outlook Express.sav\outlookrem.exe"
   
   
6. Navigate to the subkey:
   
   HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\System
   
   
7. In the right pane, delete the the value:
   
   "DisableTaskMgr" = "1"
   
   
8. Navigate to the subkey:
   
   HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer
   
   
9. In the right pane, delete the the value
   
   "NoControlPanel" = "1"
   
   
10. Navigate to the subkeys:
    
    HKEY_CLASSES_ROOT\exefile\shell\open
    HKEY_CLASSES_ROOT\batfile\shell\open
    HKEY_CLASSES_ROOT\cmdfile\shell\open
    HKEY_CLASSES_ROOT\comfile\shell\open
    HKEY_CLASSES_ROOT\piffile\shell\open
    
    
11. In the right pane, change the value to:
    
    "command" = ""%1" %*"
    
    
12. Navigate to the subkeys:
    
    HKEY_CLASSES_ROOT\vbsfile\shell\open
    HKEY_CLASSES_ROOT\vbefile\shell\open
    
    
13. In the right pane, change the value to:
    
    "command" = "%System%\WScript.exe "%1" %*"
    
    
14. Navigate to the subkey:
    
    HKEY_CLASSES_ROOT\scrfile\shell\open
    
    
15. In the right pane, change the value to:
    
    "command" = ""%1" /S"
    
    
16. Navigate to the subkey:
    
    HKEY_CLASSES_ROOT\regfile\shell\open
    
    
17. In the right pane, change the value to:
    
    "command" = "regedit.exe "%1""
    
    
18. Navigate to the subkey:
    
    HKEY_CLASSES_ROOT\inffile\shell\open\command
    
    
19. In the right pane, change the value to:
    
    %System%\NOTEPAD.EXE %1
    
    
20. Exit the Registry Editor.

5. To restore the Windows Security Center
This threat attempts to disable the features in the Windows Security Center, available in Windows XP Service Pack 2. If you are running Windows XP Service Pack 2 and would like to restore the full functionality of the Windows Security Center, please complete the following steps:

Important: If your computer is connected to a domain, you may not be able to adjust these settings. If so, contact your network administrator for more information.

1. Click Start > Control Panel.
2. Double-click the Security Center.
3. In the right pane, click Windows Firewall. The Windows Firewall appears.
4. Select On.
5. Click OK to close the Windows Firewall.
6. In the left pane of the Security Center, select Change the way Security Center alerts me.
7. Click Alert Settings.
8. Select Alert Settings, Firewall, and Virus Protection.
9. Click OK
10. Click Automatic Updates.
11. Select Automatic.
12. Click OK.
13. Exit the Security Center.

Technical Details