W32.Kitro.A.Worm - 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 and then restart the computer in Safe mode. Run a full system scan, and delete all files that are detected as W32.Kitro.A.Worm.
2. Delete the value
   
   msn C:\system32.exes
   
   from the registry keys
   
   HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
   HKEY_USER\.Default\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
   

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

To scan for and delete the infected files:

1. Obtain the most recent virus definitions. There are two ways to do this:
   • Run LiveUpdate, which is the easiest way to obtain virus definitions. These virus definitions have undergone full quality assurance testing by Symantec Security Response and are posted to the LiveUpdate servers one time 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 have undergone full quality assurance testing by Symantec Security Response. They 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.
     
2. Restart the computer in Safe mode. All Windows 32-bit operating systems except Windows NT can be restarted in Safe mode. For instructions on how to do this, read the document How to start the computer in Safe Mode.
3. 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.
4. Run a full system scan.
5. Delete all files that are detected as W32.Kitro.A.Worm.
6. Using Windows Explorer, delete the following files if they exist:
   • C:\Archiv~1\Psycho.scr
   • Psycho.scr (This file exists in the same folder as the worm.)
   • C:\Windat.dll
   • C:\Windat.vxd
   • Kiltro.dat (This file is exists in the same folder as the worm.)

To edit the registry:

CAUTION: We strongly recommend 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 back up 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 each of the following keys:
   
   HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
   HKEY_USER\.Default\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
   
4. In the right pane, delete the following value:
   
   msn C:\system32.exe
   
5. Click Registry, and click Exit.

Technical Details