Backdoor.Fivsec - 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 as Backdoor.Fivsec.
4. Delete any values added to the registry.
5. Reenable the SharedAccess service.
6. Restore the Windows Security Center.
7. Restore security settings in Internet Explorer.
   
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 as infected with Backdoor.Fivsec, click Delete.
   
   Note: If your Symantec antivirus product reports that it cannot delete an infected 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 section 4.
   

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.
   
   
4. Navigate to and delete the following subkeys:
   
   HKEY_CURRENT_USER\Software\Classes\CLSID
   \{0656A137-B161-CADD-9777-E37A75727E78}
   HKEY_CLASSES_ROOT\CLSID\{0656A137-B161-CADD-9777-E37A75727E78}
   HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\wscsvc
   HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\wscsvc
   HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer
   \SharedTaskScheduler\"{0656A137-B161-CADD-9777-E37A75727E78}"
   HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\WindowsUpdate
   \"DoNotAllowXPSP2"
   HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\SecurityCenter
   \"UpdatesDisableNotify"
   
   
5. Exit the Registry Editor.

5. 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.


6. 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.

7. To restore security settings in Internet Explorer
1. Open Internet Explorer
2. Go to the Tools menu and click on Internet Options
3. Click on the security tab
4. For each Zone, configure the security settings appropriately or click on Default Level to change settings to default.

Technical Details