W32.Blaster.F.Worm does not have a mass-mailing functionality.

Removal using the W32.Blaster.Worm Removal Tool
Symantec Security Response has developed a removal tool to clean the infections of W32.Blaster.F.Worm. Try this tool first, as it is the easiest way to remove this threat.

Click here to download W32.Blaster Removal Tool

Manual Removal
As an alternative to using the removal tool, you can manually remove this threat.
The following instructions will guide you through the steps.

1. Disable System Restore (Windows XP).
2. Update the virus definitions.
3. End the Trojan process.
4. Run a full system scan and delete all the files detected as W32.Blaster.F.Worm.
5. Reverse the changes that the Trojan made to the registry.

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

1. Disabling System Restore (Windows 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"

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. 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: Read "How to update virus definition files using the Intelligent Updater" for detailed instructions.

3. Ending the Worm process

To end the Trojan process:
Press Ctrl+Alt+Delete once.
Click Task Manager.
Click the Processes tab.
Double-click the Image Name column header to alphabetically sort the processes.
Scroll through the list and look for Enbiei.exe.
If you find the file, click it, and then click End Process.
Exit the Task Manager.

4. Scanning for and deleting the infected files

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."
Run a full system scan.
If any files are detected as infected with W32.Blaster.F.Worm, click Delete.

5. Reversing the changes made to the registry

CAUTION: 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 keys only. Read the document, "How to make a backup of the Windows registry," for instructions.

Click Start, and then click Run. (The Run dialog box appears.)
Type regedit

Then click OK. (The Registry Editor opens.)

Navigate to the key:

HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Run

In the right pane, delete the value:

"www.hidro.4t.com"="enbiei.exe"

Exit the Registry Editor

Important Notes
W32.Blaster.F.Worm exploits the DCOM RPC vulnerability. This is described in Microsoft Security Bulletin MS03-026, and a patch is available below. You must download and install the patch. In many cases, you will need to do this before continuing with the removal instructions. If you are not able to remove the infection or prevent re-infection using the following instructions, first download and install the patch.

Download patches for
Windows NT 4.0
Windows NT 4.0 Terminal Server Edition
Windows 2000
Windows XP 32 bit Edition
Windows XP 64 bit Edition
Windows Server 2003 32 bit Edition
Windows Server 2003 64 bit Edition