Skip to main content
Skip to main content
Microsoft Security Intelligence
Cart 0 items in shopping cart
Sign in
Published Dec 20, 2004 | Updated Sep 15, 2017

Worm:Win32/Gaobot.FC

Detected by Microsoft Defender Antivirus

Aliases: WORM_AGOBOT.FC (Trend Micro) W32/Gaobot.worm.gen.d (McAfee) Win32/Agobot.FA.Worm (CA) WORM_AGOBOT.CE (Trend Micro) Win32/Agobot.EX.Worm (CA) WORM_AGOBOT.AH (Trend Micro) Backdoor/Agobot.78501 (CA) Backdoor/Agobot.78493.Server (CA)

Summary

Worm:Win32/Gaobot.FC is a worm that can spread across network connections by breaking weak passwords or by exploiting vulnerabilities described in Microsoft Security Bulletins MS03-001, MS03-007, or MS03-026. After the Trojan copies and runs itself on a remote computer, it connects to an IRC server to receive commands.
To manually recover from infection by Worm:Win32/Gaobot.FC, perform the following steps:
  • Disconnect from the Internet
  • End the worm process
  • Delete the worm files from the hard disk
  • Delete the worm registry entry
  • Take steps to prevent re-infection

Disconnect from the Internet

To help ensure that your computer is not actively infecting other computers, you should 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 stop your computer from infecting other computers as well as resolve the crashing, rebooting, and performance degradation 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 sound.exe, and click End Process.
  4. Select the process syscf32.exe, and click End Process.
  5. Select the process wind32.exe, and click End Process.
  6. Select the process wupdate32.exe, and click End Process.
  7. Delete the worm files from the hard disk
After you end the worm process, you should delete the worm code from your computer.
To delete the worm files from the hard disk
  1. Click Start, and click Run.
  2. In the Open field, type %windir%\system32
  3. Click OK.
  4. Click Name to sort files by name.
  5. If sound.exe is in the list, delete it.
  6. If syscf32.exe is in the list, delete it.
  7. If wind32.exe is in the list, delete it.
  8. If wupdate32.exe is in the list, delete it.
  9. On the Desktop, right-click the Recycle Bin and click Empty Recycle Bin.
  10. Click Yes.
This removes the worm code from your computer.
If deleting files fails, use the following steps to verify that the worm file 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 sound.exe is not in the list.
  4. Confirm that syscf32.exe is not in the list.
  5. Confirm that wind32.exe is not in the list.
  6. Confirm that wupdate32.exe is not in the list.

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
    In the right pane, right-click the following values, if they exist:
    System Configuration
    Windows Registry Startup
    Windows Sound Manager
    Windows Update Manager
  4. Click Delete and click Yes to delete the value.
  5. In the left pane, navigate to the key: HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\RunServices
    In the right pane, right-click the following values, if they exist:
    System Configuration
    Windows Registry Startup
    Windows Sound Manager
    Windows Update Manager
  6. Click Delete and click Yes to delete the value.
  7. Close the Registry Editor.

Take steps to prevent re-infection

You should not reconnect your computer to the Internet until the computer is protected from re-infection. See the "Preventing Infection" section for more information.
Follow us