Summary
This article describes how to disable Citrix Application Programming Interface (API) hooks on a per-application basis.
Background
Certain Citrix Presentation Server features are implemented by loading a number of DLL modules into the address space of each application and hooking certain API calls. It is possible to prevent the loading of these modules on a per-application basis by following this procedure.
Note: Either PSE450R02W2K3028 or PSE450R02W2K3X64018 is a prerequisite before attempting this procedure on Presentation Server 4.5
Procedure
Caution! This fix requires you to edit the registry. Using Registry Editor incorrectly can cause serious problems that may require you to reinstall your operating system. Citrix cannot guarantee that problems resulting from the incorrect use of Registry Editor can be solved. Use Registry Editor at your own risk. Be sure to back up the registry before you edit it.
All Citrix API hooks can be disabled for a single executable by creating the following registry value(s).
For the 32-bit version:
Key: HKEY_LOCAL_MACHINE\SOFTWARE\Citrix\CtxHook
Value Name: ExcludedImageNames
Type: REG_SZ
Value: badapp1.exe,badapp2.exe,badapp3.exe
For the 64-bit version:
Keys: HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Citrix\CtxHook and HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Citrix\CtxHook64
Value Name: ExcludedImageNames
Type: REG_SZ
Value: badapp1.exe,badapp2.exe,badapp3.exe
More Information
CTX107824 – Citrix API Hooks (mfaphook.dll) Explained and Enumerated
