W32.HLLW.Purol - Removal

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

1. Reverse the changes that the worm made to the registry, and then restart computer. Re-install Norton AntiVirus if necessary.
2. Update the virus definitions.
3. Run a full system scan and delete all the files detected as W32.HLLW.Purol.

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

1. Reversing the changes made to the registry

CAUTION: Symantec strongly recommends that you back up the registry before you make 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, and then click OK. (The Registry Editor opens.)
   
   
3. Navigate to the key:
   
   HKEY_USERS\.DEFAULT\Software\Microsoft\Windows\CurrentVersion\Run
   
   
4. In the right pane, delete the values:
   
   "Winstart"="c:\windows\winstart32.exe"
   
   
5. Navigate to the key:
   
   HKEY_USERS\.DEFAULT\Software\Microsoft\Windows\CurrentVersion\
   RunServices
   
   
6. In the right pane, delete the values:
   
   "Winstart"="c:\windows\winstart32.exe"
   
   
7. Navigate to the key:
   
   HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Run
   
   
8. In the right pane, delete the values:
   
   "HWINFOa"="c:\windows\HWINFOa.com"
   
   
9. Delete the following registry values:
   
   HKEY_USERS\.DEFAULT\Software\Lorup\Done                                                 True
   HKEY_USERS\.DEFAULT\Software\KAZAA\LocalContent\dir0                       012345:c:\windows\MyShares
   HKEY_USERS\.DEFAULT\Software\KAZAA lite\LocalContent\dir0                012345:c:\windows\MyShares
   HKEY_USERS\.DEFAULT\Software\Grokster\LocalContent\dir0                    012345:c:\windows\MyShares
   HKEY_USERS\.DEFAULT\Software\Grokster lite\LocalContent\dir0             012345:c:\windows\MyShares
   HKEY_USERS\.DEFAULT\Software\iMesh\Client\LocalContent\dir0             012345:c:\windows\MyShares
   HKEY_USERS\.DEFAULT\Software\iMesh lite\Client\LocalContent\dir0      012345:c:\windows\MyShares
   
   
10. Exit the Registry Editor.
    
    
11. Restart the computer.
    
    
12. If the worm deleted Norton AntiVirus, re-install it.

2. 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 here. For detailed instructions on how to download and install the Intelligent Updater virus definitions from the Symantec Security Response Web site, click here.

3. 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.HLLW.Purol, click Delete.

Technical Details