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13 February 2007
Risk Impact:
Systems Affected:


Spyware.Dlder is a spyware program that submits Internet usage information to a server. It will also submit personal information, such as an IP address, the Web browser used, and a Global Unique Identifier (GUID).


The files are detected as Spyware.Dlder.


This spyware program must be manually installed. However, there are several known applications that have Spyware.Dlder within them, and that install the spyware component as the program itself is installed.

Antivirus Protection Dates

  • Initial Rapid Release version 02 October 2014 revision 022
  • Latest Rapid Release version 03 November 2019 revision 020
  • Initial Daily Certified version 20 May 2003
  • Latest Daily Certified version 04 November 2019 revision 060
  • Initial Weekly Certified release date 22 May 2003
Click here for a more detailed description of Rapid Release and Daily Certified virus definitions.

When Spyware.Dlder was installed in the test lab, it displayed several characteristics that are similar to those of backdoor Trojan Horses.

When the installer of Spyware.Dlder is executed, it does the following.
  • Does not display information on the screen.
  • Creates several files and registry keys on the system.
  • Attempts to download an additional file.

The main file of this Spyware component is Dlder.exe, which was inserted as a hidden file in the \Windows folder.

When the installer executes this spyware, it attempts to contact the site and download a file named Explorer.exe to a hidden folder in the \Windows folder, named "Explorer" (not to be confused with the Microsoft file, Explorer.exe, in the Windows folder). It is this downloaded Explorer.exe that contains the main functionality of this spyware application.

When this spyware component runs, it constantly submits Internet usage statistics to a server. This information includes the GUID, IP address, and the Web sites that have been visited since the last usage submission by Spyware.Dlder.

  1. Update the virus definitions.
  2. Delete the values added to the registry. Restart the computer.
  3. Run a full system scan and delete all the files detected as Spyware.Dlder.

For specific details on each of these steps, read the following instructions.

1. Updating the virus definitions
Symantec Security Response fully tests all the virus definitions for quality assurance before they are posted to our servers. There are two ways to obtain the most recent virus definitions:
  • Running LiveUpdate, which is the easiest way to obtain virus definitions: These virus definitions are posted to the LiveUpdate servers once each week (usually on Wednesdays), unless there is a major virus outbreak. To determine whether definitions for this threat are available by LiveUpdate, refer to the Virus Definitions (LiveUpdate).
  • Downloading the definitions using the Intelligent Updater: The Intelligent Updater virus definitions are posted on U.S. business days (Monday through Friday). You should download the definitions from the Symantec Security Response Web site and manually install them. To determine whether definitions for this threat are available by the Intelligent Updater, refer to the Virus Definitions (Intelligent Updater).

    The Intelligent Updater virus definitions are available: Read "How to update virus definition files using the Intelligent Updater" for detailed instructions.

2. Deleting the value from the registry

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

Note: This is done to make sure that all the keys are removed. They may not be there if the uninstaller removed them.

  1. Click Start, and then click Run. (The Run dialog box appears.)
  2. Type regedit

    Then click OK. (The Registry Editor opens.)

  3. Navigate to and delete the keys:


  4. Exit the Registry Editor.
  5. Restart the computer.

3. Scanning for and deleting the infected files
  1. Start Norton AntiVirus and make sure that it is configured to scan all the files. For more information, read the document, "How to configure Norton AntiVirus to scan all files."
  2. Run a full system scan.
  3. If any files are detected as Spyware.Dlder, click Delete.