Backdoor.LoxoScam - Removal

NOTE: These instructions are for all current and recent Symantec antivirus products, including the Symantec AntiVirus and Norton AntiVirus product lines.

1. Update the virus definitions
2. Run a full system scan, and delete all files that are detected as Backdoor.LoxoScam. Delete %system%\ICQS.exe and %windir%\Sys.bat if they exist.
3. Restore Rundll.exe and Findfast.exe.
4. Reverse the changes that it made to the registry.
5. (Windows 95/98/Me) Remove the line that was added to the Autoexec.bat file.
   

For details on how to do this, read the following instructions.

To update the virus definitions:
All virus definitions receive full quality assurance testing by Symantec Security Response before being posted to our servers. There are two ways to obtain the most recent virus definitions:

• Run LiveUpdate, which is the easiest way to obtain virus definitions. These virus definitions are posted to the LiveUpdate servers once each week (usually Wednesdays) unless there is a major virus outbreak. To determine whether definitions for this threat are available by LiveUpdate, look at the Virus Definitions (LiveUpdate) line at the top of this write-up.
• Download the definitions using the Intelligent Updater. Intelligent Updater virus definitions are posted on U.S. business days (Monday through Friday). They must be downloaded from the Symantec Security Response Web site and installed manually. To determine whether definitions for this threat are available by the Intelligent Updater, look at the Virus Definitions (Intelligent Updater) line at the top of this write-up.
  
  Intelligent Updater virus definitions are available here. For detailed instructions on how to download and install the Intelligent Updater virus definitions from the Symantec Security Response Web site, click here.

To scan for and delete the infected files:

1. Start your Symantec antivirus program, and make sure that it is configured to scan all files.
   • Norton AntiVirus consumer products: Read the document How to configure Norton AntiVirus to scan all files.
   • Symantec enterprise antivirus products: Read the document How to verify a Symantec Corporate antivirus product is set to scan All Files.
2. Run a full system scan.
3. If any files are detected as infected with Backdoor.LoxoScam, click Delete.
4. Using Windows Explorer, delete %system%\ICQS.exe and %windir%\Sys.bat if they exist.

To restore Rundll.exe and Findfast.exe:
Using Windows Explorer, copy C:\Windows\System\Dis.exe to the Windows folder as Rundll.exe. If you use Findfast, you should reinstall it from the Microsoft Office installation disk.


To reverse the changes that it made to the registry:

CAUTION: Symantec strongly recommends that you back up the registry before you make any changes to it. Incorrect changes to the registry can result in permanent data loss or corrupted files. Modify only the keys that are specified. Read the document How to make a backup of the Windows registry for instructions.

1. Click Start, and click Run. The Run dialog box appears.
2. Type regedit and then click OK. The Registry Editor opens.
3. Navigate to the key
   
   HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\RunServices
   
4. In the right pane, delete the value
   
   SystemDll  %windir%\SystemDll.exe
   
5. In both of these keys:
   
   HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Run
   
   HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\RunService
   
6. If the vlaue
   
   LoadPowerProfile Rundll.exe powerprof.dll,LoadCurrentPwrScheme
   
   exists, modiify it to
   
   LoadPowerProfile Rundll32.exe powerprof.dll,LoadCurrentPwrScheme
   
7. Exit the Registry Editor.

To edit the Autoexec.bat file:

NOTE: (For Windows Me users only) Due to the file-protection process in Windows Me, a backup copy of the file that you are about to edit exists in the C:\Windows\Recent folder. Symantec recommends that you delete this file before you continue with the steps in this section. To do this using Windows Explorer, go to C:\Windows\Recent, and in the right pane select the Win.ini file and delete it. It will be regenerated as a copy of the file that you are about to edit when you save your changes to that file.

1. Click Start, and click Run.
2. Type the following, and then click OK.
   
   edit c:\autoexec.bat
   
   The MS-DOS Editor opens.
   
3. Look for and delete the line
   
   %windir\Sys.bat
   
4. Click File, and click Save.
5. Click File, and click Exit.

Technical Details