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Published Sep 28, 2005 | Updated Sep 15, 2017

Worm:Win32/Dumaru.A@mm

Detected by Microsoft Defender Antivirus

Aliases: W32.Dumaru@mm (Symantec) W32/Dumaru@mm (McAfee) WORM_DUMARU.A (Trend Micro) Win32.Dumaru.A (CA)

Summary

Win32/Dumaru.A@mm is a mass-mailing worm that targets certain versions of Microsoft Windows. The worm sends a copy of itself as an attachment to e-mail addresses found on the infected computer. The worm also spreads by infecting executable files in the root directories of NTFS partitions. Win32/Dumaru.A@mm has a backdoor component that connects to an IRC server to receive commands from attackers.
To manually recover from infection by Win32/Dumaru.A@mm, follow these steps:
  1. Disconnect from the Internet.
  2. End the worm process.
  3. Delete the worm files from your computer.
  4. Delete the new worm registry entries.
  5. Reset the other 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.

End the worm process

Ending the worm process will help resolve issues caused by the worm.
To end the worm process
  1. Press CTRL+ALT+DEL once and click Task Manager.
  2. Click Processes and click Image Name to sort the running processes by name.
  3. Select the process load32.exe if it exists, and click End Process.
  4. Repeat step 3 for each of the following processes that may be running:
    dllreg.exe
    vxdmgr32.exe
    windrv.exe

Delete the worm files from your computer

To delete the worm files from your computer
  1. Click Start, and click Run.
  2. In the Open field, type %windir%, for example, C:\Windows
  3. Click OK.
  4. Click Name to sort files by name.
  5. If dllreg.exe or windrv.exe is in the list, delete it.
  6. Click Start, and click Run.
  7. In the Open field, type the name of the system folder, for example, C:Windows\system32
  8. Click OK.
  9. Click Name to sort files by name.
  10. If load32.exe or vxdmgr32.exe is in the list, delete it.
  11. On the Desktop, right-click the Recycle Bin and click Empty Recycle Bin.
  12. Click Yes to confirm the deletion.
If deleting any of the files fails, follow these steps to verify that the corresponding processes are not running:
  1. Press CTRL+ALT+DEL once and click Task Manager.
  2. Click Processes and click Image Name to sort the running processes by name.
  3. Confirm that dllreg.exe, windrv.exe, load32.exe and vxdmgr32.exe are not in the list.

Delete the new worm registry entries

Win32/Dumaru.A@mm creates entries in the Windows registry to run the worm each time Windows starts. These entries should be deleted.
To delete the new registry entries
  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 following value, if it exists: load32
  5. Click Delete and click Yes to confirm the deletion.
  6. In the left pane, navigate to the key:
    HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Windows
  7. In the right pane, right-click the following value if it exists: run
  8. Click Delete and click Yes to confirm the deletion.
  9. Close the Registry Editor.

Reset the other worm registry entry

Win32/Dumaru.A@mm modifies an entry in the Windows registry so that the worm runs each time Windows starts. This entry should be reset.
To reset 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 NT\CurrentVersion\Winlogon
  4. In the right pane, right-click the value: Shell
  5. Click Modify.
  6. Type Explorer.exe in the Value data text box and click OK.
  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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