Reading how inaccurate and confident these posts are at the same time I would add something to this one as well. Winlogon doesn't launch Taskmgr.exe for ~16 years. When you press Ctrl+Shift+Esc, Winlogon launches LaunchTM.exe, which launches Taskmgr.exe. It's not the same.
As no one knew a working example, I had to weaponize GPO Extensions on my own 😎
The practice is a bit harder than just dropping a DLL and new key in Winlogon\GPExtensions. I believe there is a simpler way, but this one works. Unfortunately it requires AD connectivity.
A 🧵⤵
1. Create the DLL exporting PFNPROCESSGROUPPOLICY callback function, as defined at 2. "return 0" is enough for the code. 3. The real code can be put into DllMain(), of course it works. 4. Make a key in Windows NT\CurrentVersion\Winlogon\GPExtensions.learn.microsoft.com/en-us/windows/…
5. The key name has to be a GUID. Non-GUID keys are ignored. 6. Within the key, two REG_SZ values should exist:
- DllName - pointing to the DLL
- ProcessGroupPolicy - containing the exported callback name from the DLL 7. Go to Windows\CurrentVersion\Group Policy\History