W32.Nopir.D

SUMMARY

W32.Nopir.D is a worm that attempts to spread through file-sharing networks such as eMule, Kazaa, Morpheus, and Gnucleus. It also lowers security settings and deletes .mp3, .avi, .mpg, .mpeg and .rar files from the compromised computer.

Protection

• Virus Definitions (LiveUpdate™ Daily) June 10, 2006
• Virus Definitions (LiveUpdate™ Weekly) June 14, 2006
• Virus Definitions (Intelligent Updater) June 10, 2006
• Virus Definitions (LiveUpdate™ Plus) June 10, 2006

Threat Assessment

Wild

• Wild Level: Low
• Number of Infections: 0 - 49
• Number of Sites: 0 - 2
• Geographical Distribution: Low
• Threat Containment: Easy
• Removal: Moderate

Damage

• Damage Level: Medium
• Deletes Files: Deletes all .mp3, .avi, .mpg, .mpeg, and .rar files from the compromised computer.
• Degrades Performance: Propagation may degrade performance.
• Compromises Security Settings: Lowers security settings and disables the Registry Editor and the Windows Firewall.

Distribution

• Distribution Level: Low
• Target of Infection: Peer to Peer applications

TECHNICAL DETAILS

When W32.Nopir.D is executed, it performs the following actions:

1. Copies itself as the following:
   
   
   • %ProgramFiles%mopyaccessootdir.exe
   • %ProgramFiles%ydc.driversforten.exe
     
     Note: %ProgramFiles% is a variable that refers to the program files folder. By default, this is C:Program Files.
     
     
2. Creates the following file:
   
   %SystemDrive%THE PUNISHMENT OF {WIN 32 NOPIR} !!!.txt
   
   Note: %SystemDrive% is a variable that refers to the drive on which Windows is installed. By default, this is drive C.
   
   
3. Copies itself using the following file names to the standard share folders of certain peer to peer file sharing applications, if they exist:
   
   
   • %ProgramFiles%eMuleIncomingAnyDVD.v6.0.0.4.Cracked-RES.by.Warez.exe
   • %ProgramFiles%KazaaMy Shared FolderAnyDVD.v6.0.0.4.Cracked-RES.by.Warez.exe
   • %ProgramFiles%StreamCastMorpheusMy Shared Folder
     AnyDVD.v6.0.0.4.Cracked-RES.by.Warez.exe
   • %ProgramFiles%GnucleusDownloadsAnyDVD.v6.0.0.4.Cracked-RES.by.Warez.exe
     
     
4. Adds the values:
   
   "vysmet" = "%ProgramFiles%mopyaccessootdir.exe"
   "loading" = "%ProgramFiles%ydc.driversforten.exe"  
   
   to the registry subkey:
   
   HKEY_LOCAL_MACHINESOFTWAREMicrosoftWindowsCurrentVersionRun
   
   so that it runs every time Windows starts.
   
   
5. Modifies the value:
   
   "(Default)" = "%ProgramFiles%ydc.driversforten.exe"
   
   in the registry subkeys:
   
   HKEY_CLASSES_ROOTexefileshellopencommand
   HKEY_CLASSES_ROOTatfileshellopencommand
   HKEY_CLASSES_ROOTcmdfileshellopencommand
   HKEY_CLASSES_ROOTcomfileshellopencommand
   HKEY_CLASSES_ROOTpiffileshellopencommand
   HKEY_CLASSES_ROOTvbsfileshellopencommand
   HKEY_CLASSES_ROOTvbefileshellopencommand
   HKEY_CLASSES_ROOTscrfileshellopencommand
   HKEY_CLASSES_ROOTscrfileshellinstallcommand
   HKEY_CLASSES_ROOTscrfileshellconfigcommand
   HKEY_CLASSES_ROOTegfileshellopencommand
   HKEY_CLASSES_ROOTinffileshellopencommand
   HKEY_CLASSES_ROOTinffileshellinstallcommand
   
   
6. Modifies the values:
   
   "DisableTaskMgr" = "1"
   "DisableRegistryTools" = "1"
   
   in the registry subkey:
   
   HKEY_CURRENT_USERSoftwareMicrosoftWindowsCurrentVersion
   PoliciesSystem
   
   to disable the Task Manager and registry tools.
   
   
7. Modifies the values:
   
   "[NUMBER]" = "wscript.exe"
   "[NUMBER]" = "regedit.exe"
   
   in the registry subkey:
   
   HKEY_CURRENT_USERSoftwareMicrosoftWindowsCurrentVersionPolicies
   ExplorerDisallowRun
   
   to disable the registry editor and Windows Firewall.
   
   
8. Modifies the values:
   
   "NoControlPanel" = "1"
   "DisallowRun" = "1"
   
   in the registry subkey:
   
   HKEY_CURRENT_USERSoftwareMicrosoftWindowsCurrentVersion
   PoliciesExplorer
   
   to disable access to the Control Panel.
   
   
9. Modifies the values:
   
   "AUOptions" = "4"
   "Config Ver" = "1"
   "ScheduledInstallDay" = "0"
   "ScheduledInstallTime" = "3"
   
   in the registry subkey:
   
   HKEY_LOCAL_MACHINESoftwareMicrosoftWindowsCurrentVersion
   WindowsUpdateAuto Update
   
   to disable Windows Update.
   
   
10. Modifies the value:
    
    "DisableSR" = "1"
    
    in the registry subkey:
    
    HKEY_LOCAL_MACHINESoftwareMicrosoftWindows NTSystemRestore
    
    to disable System Restore.
    
    
11. May modify the following subkeys:
    
    HKEY_LOCAL_MACHINESOFTWAREClassesCLSID
    {4BA7CB52-5AF5-6B8E-FECC-5DBE2D300F06}
    HKEY_CURRENT_USERSoftwareMicrosoftWindowsCurrentVersionExplorer
    UserAssist{75048700-EF1F-11D0-9888-006097DEACF9}
    
    
12. Modifies the value:
    
    "1803" = "3"
    
    in the registry subkeys:
    
    HKEY_LOCAL_MACHINESOFTWAREMicrosoftWindowsCurrentVersionInternet Settingsones3
    HKEY_CURRENT_USERSOFTWAREMicrosoftWindowsCurrentVersionInternet Settingsones3
    
    
13. Adds the following legitimate registry subkey:
    
    HKEY_LOCAL_MACHINESOFTWAREWindows 3.1 Migration Status
    
    
14. Displays an anti-piracy image.
    
    
15. Deletes all .mp3, .avi, .mpg, .mpeg, and .rar files from the compromised computer.

Recommendations

Symantec Security Response encourages all users and administrators to adhere to the following basic security "best practices":

• Turn off and remove unneeded services. By default, many operating systems install auxiliary services that are not critical, such as an FTP server, telnet, and a Web server. These services are avenues of attack. If they are removed, blended threats have less avenues of attack and you have fewer services to maintain through patch updates.
• If a blended threat exploits one or more network services, disable, or block access to, those services until a patch is applied.
• Always keep your patch levels up-to-date, especially on computers that host public services and are accessible through the firewall, such as HTTP, FTP, mail, and DNS services (for example, all Windows-based computers should have the current Service Pack installed.). Additionally, please apply any security updates that are mentioned in this writeup, in trusted Security Bulletins, or on vendor Web sites.
• Enforce a password policy. Complex passwords make it difficult to crack password files on compromised computers. This helps to prevent or limit damage when a computer is compromised.
• Configure your email server to block or remove email that contains file attachments that are commonly used to spread viruses, such as .vbs, .bat, .exe, .pif and .scr files.
• Isolate infected computers quickly to prevent further compromising your organization. Perform a forensic analysis and restore the computers using trusted media.
• Train employees not to open attachments unless they are expecting them. Also, do not execute software that is downloaded from the Internet unless it has been scanned for viruses. Simply visiting a compromised Web site can cause infection if certain browser vulnerabilities are not patched.

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. Download the tool to reset shellopencommand registry keys.
3. Restart the computer in Safe mode or Safe mode with Command Prompt.
4. Restore access to the Registry Editor.
5. Delete any values added to the registry.
6. Update the virus definitions.
7. Run a full system scan.
8. Reenable the SharedAccess service (Windows 2000/XP only)
   

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 download the tool to reset shellopencommand registry keys:

1. Download the file UnHookExec.inf and save it to C:Windowsinf.
   
   Note:
   • If you cannot connect to the Internet from the infected computer, download to an uninfected computer then save it to a floppy disk. Then take the floppy disk and insert it in the floppy disk drive of the infected computer and save the file to C:Windowsinf.
   • The tool has a .inf file extension.

3. To restart the computer in Safe mode or Safe mode with Command Prompt
Follow the instructions for your operating system.

Windows 2000

1. Shut down the computer, and then turn off the power. Wait for at least 30 seconds, and then restart the computer
2. When you see the black and white Starting Windows bar at the bottom of the screen, press the F8 key (usually on the top row of the keyboard).
3. In the Windows 2000 Advanced Options Menu, select Safe mode with Command Prompt, and then press Enter.
   
   Once the computer opens to a window with a command prompt (you should see a line of text and a blinking cursor), proceed with the next section.

Windows XP

1. Shut down the computer, and then turn off the power. Wait for at least 30 seconds, and then restart the computer. The computer begins processing a set of instructions known as the Basic Input/Output System (BIOS). What is displayed depends on the BIOS manufacturer. Some computers display a progress bar that refers to the word BIOS, while others may not display any indication that this process is occurring.
2. As soon as the BIOS has finished loading, begin tapping the F8 key on your keyboard. Continue to do so until the Windows Advanced Options menu appears. If you begin tapping the F8 key too soon, some computers will display a "keyboard error" message. To avoid this, restart the computer and try again.
3. In the Windows 2000 Advanced Options Menu, select Safe mode with Command Prompt, and then press Enter.
   
   Once the computer opens to a window with a command prompt (you should see a line of text and a blinking cursor), proceed with the next section.

4. To restore access to the Registry Editor
Since this threat prevents access to the Registry Editor, you must restore access in order to fully remove the threat. Complete the following steps to restore access.

Type the following command:

c:windowssystem32undll32.exe setupapi.dll,InstallHinfSection DefaultInstall 132 c:windowsinfUnHookExec.inf

5. 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. Type regedit
2. Click OK.
3. Navigate to the subkey:
   
   HKEY_LOCAL_MACHINESOFTWAREMicrosoftWindowsCurrentVersionRun
   
   
4. In the right pane, delete the values:
   
   "vysmet" = "%ProgramFiles%mopyaccessootdir.exe"
   "loading" = "%ProgramFiles%ydc.driversforten.exe"
   
   
5. Navigate to the subkey:
   
   HKEY_CURRENT_USERSoftwareMicrosoftWindowsCurrentVersionPolicies
   ExplorerDisallowRun
   
   
6. In the right pane, delete the values:
   
   "[NUMBER]" = "regedit.exe"
   "[NUMBER]" = "wscript.exe"
   
   
7. Navigate to the subkey:
   
   HKEY_LOCAL_MACHINESoftwareMicrosoftWindowsCurrentVersion
   WindowsUpdateAuto Update
   
   
8. In the right pane, delete the values:
   
   "ScheduledInstallDay" = "0"
   "ScheduledInstallTime" = "3"
   
   
9. Navigate to and delete the following subkeys:
   
   HKEY_LOCAL_MACHINESOFTWAREClassesCLSID
   {4BA7CB52-5AF5-6B8E-FECC-5DBE2D300F06}
   HKEY_CURRENT_USERSoftwareMicrosoftWindowsCurrentVersionExplorer
   UserAssist{75048700-EF1F-11D0-9888-006097DEACF9}
   
   
10. Navigate to the subkey:
    
    HKEY_CLASSES_ROOTinffileshellopencommand
    
    
11. In the right pane, reset the value:
    
    "(Default)" = "%ProgramFiles%ydc.driversforten.exe"
    
    to:
    
    "(Default)" = "%SystemRoot%System32NOTEPAD.EXE %1"
    
    
12. Navigate to the subkey:
    
    HKEY_CLASSES_ROOTinffileshellinstallcommand
    
    
13. In the right pane, reset the value:
    
    "(Default)" = "%ProgramFiles%ydc.driversforten.exe"
    
    to:
    
    "(Default)" = "%SystemRoot%System32undll32.exe setupapi,InstallHinfSection DefaultInstall 132 %1"
    
    
14. Navigate to the registry subkeys:
    
    HKEY_CLASSES_ROOTscrfileshellinstallcommand"(Default)" = "%ProgramFiles%ydc.driversforten.exe"
    HKEY_CLASSES_ROOTscrfileshellconfigcommand"(Default)" = "%ProgramFiles%ydc.driversforten.exe"
    HKEY_CLASSES_ROOTcmdfileshellopencommand"(Default)" = "%ProgramFiles%ydc.driversforten.exe"
    HKEY_CLASSES_ROOTvbsfileshellopencommand"(Default)" = "%ProgramFiles%ydc.driversforten.exe"
    HKEY_CLASSES_ROOTvbefileshellopencommand"(Default)" = "%ProgramFiles%ydc.driversforten.exe"
    
    
15. In the right pane, reset the values to:
    
    HKEY_CLASSES_ROOTscrfileshellinstallcommand"(Default)" = "rundll32.exe desk.cpl,InstallScreenSaver %l"
    HKEY_CLASSES_ROOTscrfileshellconfigcommand"(Default)" = ""%1""
    HKEY_CLASSES_ROOTcmdfileshellopencommand"(Default)" = ""%1" %*"
    HKEY_CLASSES_ROOTvbsfileshellopencommand"(Default)" = "%Windir%System32WScript.exe "%1" %*"
    HKEY_CLASSES_ROOTvbefileshellopencommand"(Default)" = "%Windir%System32WScript.exe "%1" %*"
    
    
16. Navigate to the registry subkey:
    
    HKEY_CURRENT_USERSoftwareMicrosoftWindowsCurrentVersion
    PoliciesSystem
    
    
17. In the right pane, restore the following values to their original settings:
    
    "DisableTaskMgr" = "1"
    "DisableRegistryTools" = "1"
    
    
18. Navigate to the registry subkey:
    
    HKEY_CURRENT_USERSoftwareMicrosoftWindowsCurrentVersion
    PoliciesExplorer
    
    
19. In the right pane, restore the following values to their original settings:
    
    "NoControlPanel" = "1"
    "DisallowRun" = "1"
    
    
20. Navigate to the registry subkey:
    
    HKEY_LOCAL_MACHINESoftwareMicrosoftWindowsCurrentVersion
    WindowsUpdateAuto Update
    
    
21. In the right pane, restore the following values to their original settings:
    
    "AUOptions" = "4"
    "Config Ver" = "1"
    
    
22. Navigate to the registry subkey:
    
    HKEY_LOCAL_MACHINESoftwareMicrosoftWindows NTSystemRestore
    
    
23. In the right pane, restore the following value to its original setting:
    
    "DisableSR" = "1"
    
    
24. Navigate to the registry subkeys:
    
    HKEY_LOCAL_MACHINESOFTWAREMicrosoftWindowsCurrentVersionInternet Settingsones3
    HKEY_CURRENT_USERSOFTWAREMicrosoftWindowsCurrentVersionInternet Settingsones3
    
    
25. In the right pane, restore the following value to its original setting:
    
    "1803" = "3"
    
    
26. Exit the Registry Editor.
    
    
27. Restart the computer in Normal Mode.
    
    

6. 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:
  • If you use Norton AntiVirus 2006, Symantec AntiVirus Corporate Edition 10.0, or newer products, LiveUpdate definitions are updated daily. These products include newer technology.
  • If you use Norton AntiVirus 2005, Symantec AntiVirus Corporate Edition 9.0, or earlier products, LiveUpdate definitions are updated weekly. The exception is major outbreaks, when definitions are updated more often.
• 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 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.

7. To run a full system scan

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, follow the instructions displayed by your antivirus program.

Important: If you are unable to start your Symantec antivirus product or the product reports that it cannot delete a detected file, you may need to stop the risk from running in order to remove it. To do 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.

8. To reenable the SharedAccess service (Windows 2000/XP only)
The SharedAccess service is responsible for maintaining Internet Connection Sharing and the Windows Firewall/Internet Connection Firewall applications in Windows. (The presence and names of these applications vary depending on the operating system and service pack you are using.) To protect your computer and maintain network functionality, re-enable this service if you are using any of these programs.


Windows XP Service Pack 2
If you are running Windows XP with Service Pack 2 and are using the Windows Firewall, the operating system will alert you when the SharedAccess service is stopped, by displaying an alert balloon saying that your Firewall status is unknown. Perform the following steps to ensure that the Windows Firewall is re-enabled:

1. Click Start > Control Panel.
   
   
2. Double-click the Security Center.
   
   
3. Ensure that the Firewall security essential is marked ON.
   
   Note: If the Firewall security essential is marked on, your Windows Firewall is on and you do not need to continue with these steps.
   
   If the Firewall security essential is not marked on, click the "Recommendations" button.
   
   
4. Under "Recommendations," click Enable Now. A window appears telling you that the Windows Firewall was successfully turned on.
   
   
5. Click Close, and then click OK.
   
   
6. Close the Security Center.

Windows 2000 or Windows XP Service Pack 1 or earlier
Complete the following steps to re-enable the SharedAccess service:

1. Click Start > Run.
2. Type services.msc
   
   Then click OK.
   
   
3. Do one of the following:
   
   • Windows 2000: Under the Name column, locate the "Internet Connection Sharing (ICS)" service and double-click it.
   • Windows XP: Under the Named column, locate the "Internet Connection Firewall (ICF) / Internet Connection Sharing (ICS)" service and double-click it.
     
     
4. Under "Startup Type:", select "Automatic" from the drop-down menu.
   
   
5. Under "Service Status:", click the Start button.
   
   
6. Once the service has completed starting, click OK.
   
   
7. Close the Services window.