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Microsoft Security Intelligence
Published Dec 20, 2004 | Updated Sep 15, 2017

Worm:Win32/Mydoom.AB@mm

Detected by Microsoft Defender Antivirus

Aliases: W32.Mydoom.AB@mm (Symantec) WORM_MYDOOM.W (Trend Micro) W32/Mydoom.ab@MM (McAfee) Win32/Mydoom.AA.Worm (CA)

Summary

Win32/Mydoom.AB@mm is a mass-mailing worm that sends itself to e-mail addresses it finds on the infected computer.
To manually recover from infection by Win32/Mydoom.AB@mm, perform the following steps:
  1. Disconnect from the Internet.
  2. Restart the computer in safe mode.
  3. Remove the worm service.
  4. Delete the worm files from your computer.
  5. Delete the worm registry entry.
  6. Restart your computer.
  7. Take steps to prevent re-infection.

Disconnect from the Internet

To help ensure that your computer is not actively infecting other computers, disconnect it from the Internet before proceeding. Print this Web page or save a copy on your computer; then unplug your network cable and disable your wireless connection. You can reconnect to the Internet after completing these steps.

Restart the computer in safe mode

To start your computer in safe mode
  1. Remove all floppy disks and CDs from your computer, and then restart your computer.
  2. When prompted, press F8. If Windows starts without displaying the Please select the operating system to start menu, restart your computer. Press F8 after the firmware POST process completes, but before Windows displays graphical output.
  3. From the Windows Advanced Options Menu, select a safe mode option.

Remove the worm service

Removing the worm service will help stop your computer from infecting other computers.
To remove the worm service
  1. On the Start menu, click Control Panel.
  2. Click Administrative Tools and double-click Services.
  3. Right-click the NetBios Ext service.
  4. If the service is running, click Stop.
  5. Right-click the service again and click Properties.
  6. Under Startup Type, change the type to Disabled.

Delete the worm files from your computer

After you end the worm process, delete the worm code from your computer.
To delete the worm files from your computer
  1. Click Start, and click Run.
  2. In the Open field, type %windir%
  3. Click OK.
  4. Click Name to sort files by name.
  5. If the files smss.exe, csrss.exe, winlogon.exe, or services.exe are in the list, delete them.
  6. On the Desktop, right-click the Recycle Bin and click Empty Recycle Bin .
  7. Click Yes .
This removes the worm code from your computer. If deleting files fails, follow the steps of "Remove the worm service" to verify that worm is not running.

Delete the worm registry entry

To delete the worm registry entry
  1. On the Start menu, click Run.
  2. Type regedit and click OK.
  3. In the left pane, navigate to the key:
    HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Run
  4. In the right pane, right-click the value:
    RPCserv
  5. Select Delete.
  6. Click Yes to delete the value.
  7. Close the Registry Editor.

Restart your computer

To restart your computer
  1. On the Start menu, click Shut Down.
  2. Select Restart from the drop-down list and click OK.

Take steps to prevent re-infection

Do not reconnect your computer to the Internet until the computer is protected from re-infection. See the Preventing Infection section for more information.
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