W32.DSS.Trojan - Removal

Download the latest virus definitions, scan and delete any infected files, and remove the entries left by the Trojan. For Windows NT/2000/XP, this means editing the registry to remove the entries that are left by W32.DSS.Trojan. For Windows 95/98/Me, remove the Trojan entry from the Shell= line in the System.ini file.

To delete files that are detected as W32.DSS.TrojanWorm:

1. Obtain the most recent virus definitions. There are two ways to do this:
   • Run LiveUpdate. LiveUpdate 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. Start Norton AntiVirus (NAV), and make sure that NAV is configured to scan all files. For instructions on how to do this, read the document How to configure Norton AntiVirus to scan all files.
3. Run a full system scan.
4. Delete all files that are detected as W32.DSS.Trojan.

To edit the registry:

NOTE: This step is for Windows NT/2000/XP only

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 following key:
   
   HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\WindowsNT\CurrentVersion\Winlogon
   
4. In the right pane, edit the following value and remove openme.exe.
   
   Shell Explorer.exe  openme.exe
   
   To edit the entry, select the key, click Edit, and click Modify. Select Openme.exe in the Value Data field and press Delete. Click Yes to the prompts that appear.
   
   NOTE: When you have finished, the value should look like this:
   
   Shell Explorer.exe  
   
5. Exit the Registry Editor.

To edit System.ini:

NOTES:

• These steps are for Windows 95/98/Me only.
• (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:\windows\system.ini
   
   The MS-DOS Editor opens.
   
   NOTE: If Windows is installed in a different location, make the appropriate path substitution.
   
3. In the [boot] section of the file, look for a line similar to the following:
   
   shell = explorer.exe openme.exe
   
4. If it exists, select openme.exe and then press Delete. When you have finished, only shell = explorer.exe should remain.
5. Click File, and click Save.
6. Click File, and click Exit.

Technical Details