QUESTION AND ANSWER

Did the Launcher name change to GoToMeeting Opener?

Issue

Objective

Environment

  • GoToMeeting
  • GoToWebinar
  • GoToTraining

Procedure

Answer

The Launcher was renamed to "Opener" on 10/24/16. This change is necessary to handle a Windows security issue. If you no longer can launch the software due to this change please reach out to your IT department or allow the Opener.exe through your computer's firewall.

  • This change influences all launch flows on Windows which are currently named "[ProductName] Launcher.exe".
  • Products launch flows which are currently named "[ProductName] Installer.exe" are NOT affected.

The new Launcher App download name will be [Product Name] Opener.exe instead of [Product Name] Launcher.exe (e.g. not GoToMeeting Launcher.exe anymore, but now GoToMeeting Opener.exe).
User-added image

Cause

Resolution

Additional Information

Technical Background:
Some Application Compatibility ("AppCompat") DLLs are automatically loaded by Windows when the Launcher App is currently started. This happens before any Launcher App code is reached, therefore the Launcher App is not able to perform any actions to prevent DLL hijacking (https://en.wikipedia.org/wiki/Dynamic-link_library#DLL_hijacking) in this case. The AppCompat dll loading is activated by Windows for many *.exe files one rule is, that it is loaded for all executables which have the string "launch" in the exe file name.
Windows is searching the AppCompat DLLs in the local folder of the Launcher App (which is the "Download" folder in the first time join flow) when it is started. Only if the DLLs could not be found there, the system DLLs are loaded. These local DLLs could be placed there by an attacker. So the Launcher App would execute these malicious DLLs.
Since we are starting from the Download folder (for the first time join flow) the risk that a malicious DLL can be placed in this folder is very high.

In order to NOT trigger the AppCompat logic by Windows when the Launcher App is started, we had to remove the word "Launcher" from our downloaded filename.