Removing LeChuk Worm or WORM_VB.FKO

Solution

(Note: Close all instances of Internet Explorer before proceeding with the following solution.)

Terminating the Malware Program

This procedure terminates the running malware process.
Open Windows Task Manager.
    • On Windows 98 and ME, press CTRL+ALT+DELETE
    • On Windows NT, 2000, XP, and Server 2003, press CTRL+SHIFT+ESC, then click
       the Processes tab.
      In the list of running programs*, locate the process:
              LeChucK.exe
              wins.exe

Select the malware process, then press either the End Task or the End Process button, depending on the version of Windows on your computer.
To check if the malware process has been terminated, close Task Manager, and then open it again.

Close Task Manager.

*NOTE: On computers running Windows 98 and ME, Windows Task Manager may not show certain processes. You can use a third party process viewer such as Process Explorer to terminate the malware process.

On computers running all Windows platforms, if the process you are looking for is not in the list displayed by Task Manager or Process Explorer, continue with the next solution procedure, noting additional instructions. If the malware process is in the list displayed by either Task Manager or Process Explorer, but you are unable to terminate it, restart your computer in safe mode.

Sometimes, you may not be able to remove the file with a message that you do not have sufficient privilleges to complete the operation.


You will need to manually restore access to registry..

Removing Autostart Entries from the Registry

This solution deletes registry entries added by this malware. Before performing the steps below, make sure you know how to back up the registry and how to restore it if a problem occurs. Refer to this Microsoft article for more information about modifying your computer's registry.
Open Registry Editor. Click Start>Run, type REGEDIT, then press Enter.
In the left panel, double-click the following:
HKEY_CLASSES_ROOT>batfile>shell>open>command
In the right panel, locate the entry:
(Default) = "%System%\wins.exe "%1" %*"
Right-click on the value name and choose Modify. Change the value data of this entry to:
"%1" %*
In the left panel, double-click the following:
HKEY_CLASSES_ROOT>cmdfile>shell>open>command
In the right panel, locate the entry:
(Default) = "%System%\wins.exe "%1" %*"
Right-click on the value name and choose Modify. Change the value data of this entry to:
"%1" %*
In the left panel, double-click the following:
HKEY_CLASSES_ROOT>comfile>shell>open>command
In the right panel, locate the entry:
(Default) = "%System%\wins.exe "%1" %*"
Right-click on the value name and choose Modify. Change the value data of this entry to:
"%1" %*
In the left panel, double-click the following:
HKEY_CLASSES_ROOT>exefile>shell>open>command
In the right panel, locate the entry:
(Default) = "%System%\wins.exe "%1" %*"
Right-click on the value name and choose Modify. Change the value data of this entry to:
"%1" %*
In the left panel, double-click the following:
HKEY_CLASSES_ROOT>piffile>shell>open>command
In the right panel, locate the entry:
(Default) = "%System%\wins.exe "%1" %*"
Right-click on the value name and choose Modify. Change the value data of this entry to:
"%1" %*
Close Registry Editor.

Restoring AUTORUN.INF/s
Right-click Start then click Search... or Find..., depending on the version of Windows you are running.
In the Named input box, type:
AUTORUN.INF
In the Look In drop-down list, select a drive, then press Enter.
Select the file, then open using Notepad.
Check if the following lines are present in the file:
OPEN=%WINDOWS%\Spolis.exe
shell\open=Abrir
shell\open\Command=%WINDOWS%\Spolis.exe
shell\open\Default=1
shell\explore=Explorar
shell\explore\Command=%WINDOWS%\Spolis.exe
If the lines are present, delete the file.
Repeat steps 3 to 6 for AUTORUN.INF files in the remaining removable drives.
Close Search Results.

Deleting the Malware File(s)
Right-click Start then click Search... or Find..., depending on the version of Windows you are running.
In the Named input box, type:
%system%\CC.dll
In the Look In drop-down list, select the drive that contains Windows, then press Enter.
Once located, select the file then press SHIFT+DELETE.
Repeat steps 2-4 for the following file(s):
%system%\LeChucK.hta
%system%\zip32.dll

Important Windows ME/XP Cleaning Instructions

Users running Windows ME and XP must disable System Restore to allow full scanning of infected computers.

WORM_VB.FKO or LeChuck.exe - Information

WORM_VB.FKO commonly known as LeChuck.exe

File type: PE
Memory resident: Yes
Size of malware: 102,840 Bytes
Initial samples received on: Aug 29, 2007
Payload 1: Downloads files

Arrival

This worm is dropped by other malware. It is downloaded unknowingly by a user when visiting malicious Web sites.

Installation

This worm drops the following copies of itself:
%System%\cmd.com
%System%\LeChucK.exe
%System%\wins.exe
%Windows%\regedit.com
%Windows%\spolis.exe

(Note: %System% is the Windows system folder, which is usually C:\Windows\System on Windows 98 and ME, C:\WINNT\System32 on Windows NT and 2000, or C:\Windows\System32 on Windows XP and Server 2003. %Windows% is the Windows folder, which is usually C:\Windows or C:\WINNT.)

It drops the following non-malicious files/components:
%System%\CC.dll
%System%\LeChucK.hta
%System%\zip32.dll

Autostart Techniques

This worm employs registry shell spawning so that it executes when files of certain types are run. It does this by creating some registry entries.

This worm creates registry entries to disable Task Manager.
This worm drops copies of itself in all physical and removable drives.
It also drops AUTORUN.INF to execute its dropped copies when the said drives are accessed.

The file AUTORUN.INF file contains the following strings:

   OPEN=%windows%\Spolis.exe
   shell\open=Abrir
   shell\open\Command=%windows%\Spolis.exe
   shell\open\Default=1
   shell\explore=Explorar
   shell\explore\Command=%windows%\Spolis.exe

Affected Platforms

This worm runs on Windows 98, ME, NT, 2000, XP, and Server 2003.

Enabling The Registry Editor

If some malware disables the Registry Editor, use the following steps to restore it.

1. Open Notepad. Click Start>Run, type Notepad, then press Enter.
2. Copy and paste the following:

 on error resume next
 set jzw = CreateObject("Wscript.Shell")
 jzw.regwrite  "HKCU\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System\DisableRegistryTools",0,"REG_DWORD"
 jzw.regwrite  "HKCU\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System\DisableTaskMgr",0,"REG_DWORD"
 [HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\System]
  "DisableRegistryTools" = dword:00000000

3. Save this file as C:\RESTORE.REG.
4. Click Start>Run, type C:\RESTORE.REG, then press Enter,
5. Click Yes at the prompt of the message box.