W32.Appix.D.Worm - Removal

NOTES:

• These instructions are for all current and recent Symantec antivirus products, including the Symantec AntiVirus and Norton AntiVirus product lines.
• This worm will infect only Windows NT/2000/XP computers. However, it is still possible for the worm's files to be on other operating systems. If you are running Windows 95/98/Me, you should still update the virus definitions and scan the computer as described in steps 4 and 5.

1. Stop the worm processes.
2. Reverse the changes that the worm made to the registry.
3. Restart your Symantec antivirus product.
4. Update the virus definitions.
5. Run a full system scan, and delete all files that are detected as W32.Appix.D.Worm or PHP.Appix.
   

For details on how to do this, read the following instructions.

To stop the worm processes in Windows NT/2000/XP

1. Press Ctrl+Alt+Delete one time.
2. Click Task Manager.
3. Click the Processes tab.
4. Double-click the Image Name column header to sort the processes alphabetically.
5. Scroll through the list, and look for the following names:
   • Appbsvc.exe
   • Appboost.exe
6. For each of these processes that you find, click the name, and then click End Process.
7. Close the Task Manager.

To reverse the changes that the worm made to the registry:

Copy Regedit.exe to Regedit.com:
Because the worm modified the registry so that you cannot run .exe files, you must first make a copy of the Registry Editor as a file with the .com extension, and then run that file.

1. Do one of the following, depending on which version of Windows you are running:
   • Windows NT/2000 users:
     1. Click Start, and click Run.
     2. Type the following and then press Enter:
        
        command
        
        A DOS window opens.
        
     3. Type the following, and then press Enter:
        
        cd \winnt
        
     4. Go on to step 2 of this section.
   • Windows XP:
     1. Click Start, and click Run.
     2. Type the following, and then press Enter:
        
        command
        
        A DOS window opens.
        
     3. Type the following, and then press Enter after typing each one:
        
        cd\
        cd \windows
        
     4. Proceed to step 2 of this section.
        
2. Type the following, and then press Enter:
   
   copy regedit.exe regedit.com
   
3. Type the following, and then press Enter:
   
   start regedit.com
   
   The Registry Editor will open in front of the DOS window. After you finish editing the registry, exit the Registry Editor, and then exit the DOS window, as well.
   

1. Proceed to the next section, "To edit the registry and remove keys and changes made by the worm," only after you have performed the previous steps.


To edit 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 only the keys that are specified. Read the document How to make a backup of the Windows registry for instructions.

1. Navigate to and select the key
   
   HKEY_LOCAL_MACHINE\Software\Classes\exefile\shell\open\command
   
   CAUTION: The HKEY_LOCAL_MACHINE\Software\Classes key contains many subkey entries that refer to other file extensions. One of these file extensions is .exe. Changing this extension can prevent any files ending with an .exe extension from running. Make sure that you browse all the way along this path until you reach the \command subkey.
   
   Make sure that you modify the HKEY_LOCAL_MACHINE\Software\Classes\exefile\shell\open\command subkey that is shown in the following figure:
   
   <<=== NOTE: Modify this key.
   
2. In the right pane, double-click the (Default) value.
3. Delete the current value data, and then type: "%1" %* (That is, type the following characters: quote-percent-one-quote-space-percent-asterisk.)
   
   NOTE: Make sure that you completely delete all value data in the command key before you type the correct data. If you leave a space at the beginning of the entry, any attempt to run program files will result in the error message, "Windows cannot find .exe." If this happens to you, start over at the beginning of this document, and make sure that you completely remove the current value data.
   
4. Navigate to and delete this key:
   
   HKEY_CURRENT_USER\Software\Microsoft\Mails
   
5. Navigate to and delete the key
   
   HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\appboost
   
6. Exit the Registry Editor.

To restart your Symantec antivirus product:
How you do this varies with the product. Please read the product documentation for instructions on how to do this.

To update the virus definitions:
All virus definitions receive full quality assurance testing by Symantec Security Response before being posted to our servers. There are two ways to obtain the most recent virus definitions:

• Run LiveUpdate, which is the easiest way to obtain virus definitions. These virus definitions are posted to the LiveUpdate servers once each week (usually Wednesdays) unless there is a major virus outbreak. To determine whether definitions for this threat are available by LiveUpdate, look at the Virus Definitions (LiveUpdate) line at the top of this write-up.
• Download the definitions using the Intelligent Updater. Intelligent Updater virus definitions are posted on U.S. business days (Monday through Friday). They must be downloaded from the Symantec Security Response Web site and installed manually. To determine whether definitions for this threat are available by the Intelligent Updater, look at the Virus Definitions (Intelligent Updater) line at the top of this write-up.
  
  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.

To scan for and delete the infected files:

1. Start your Symantec antivirus program, and make sure that it is configured to scan all files.
   • Norton AntiVirus consumer products: Read the document How to configure Norton AntiVirus to scan all files.
   • Symantec enterprise antivirus products: Read the document How to verify 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.Appix.D.Worm or PHP.Appix, click Delete.

Technical Details