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Published Aug 22, 2005 | Updated Sep 15, 2017

Worm:Win32/Esbot.D

Detected by Microsoft Defender Antivirus

Aliases: W32/IRCbot.worm.gen (McAfee) WORM_ESBOT.B (Trend Micro) Win32/Esbot.B!Worm (CA)

Summary

Worm:Win32/Esbot.D is a network worm that targets Microsoft Windows 2000 computers by exploiting the Windows Plug-and-Play buffer overflow vulnerability that is fixed with Microsoft Security Bulletin MS05-039. The worm can also infect computers running other Windows operating systems if it is delivered through e-mail, instant messaging, or other routes. The worm has a backdoor component that connects to an IRC server to receive commands from attackers.
To manually recover from infection by Worm:Win32/Esbot.D, follow these steps:
  1. Install Windows security update MS05-039.
  2. Disconnect from the Internet.
  3. Restart your computer in safe mode.
  4. End the worm process.
  5. Delete the registry key for the worm service.
  6. Delete the worm file.
  7. Restart your computer.
  8. Take steps to prevent re-infection.

Install Windows security update MS05-039

To install MS05-039 using Windows Update
  1. Go to the Windows Update Web site at windowsupdate.microsoft.com.
  2. On the Windows Update site, click Scan for Updates. Windows Update scans your computer and returns a list of critical updates, including service packs.
  3. In the Pick updates to install list, click Critical Updates and Service Packs. Windows Update creates a list of the updates appropriate for your computer, including MS05-039 if it is not installed. Critical updates are selected for download automatically.
  4. Click Review and install updates, and then click Install Now. You may need to restart your computer after installing the updates.

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 your computer in safe mode

To start your the 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.  

Delete the registry key for the worm service

Worm:Win32/Esbot.D creates a key in the Windows registry that registers the worm as a service. This entry should be deleted.
To delete the registry key for the worm service
  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\SYSTEM\CurrentControlSet\Services\mousesync
  4. Right-click the key and click Delete.
  5. Click Yes to confirm the deletion.
  6. Close the Registry Editor.

Delete the worm file

To delete the worm file from your computer
  1. Click Start, and click Run.
  2. In the Open field, type the name of the Windows system folder, for example, C:\Winnt\System32
  3. Click OK.
  4. Click Name to sort files by name.
  5. If mousesync.exe is in the list, delete it.
  6. On the Desktop, right-click the Recycle Bin and click Empty Recycle Bin.
  7. Click Yes.
If deleting the file fails, follow these steps to verify that mousesync.exe is 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 mousesync.exe is not in the list.

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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