As we can read,
A key sequence that begins the process of logging on or off. The default sequence is CTRL+ALT+DEL.
I've been using Win+L to lock my desktop, since I find it easier to use, and I even recommend that to other people. For my own research, this combination cannot be registered as a hotkey either. But: I have no official documentation on it.
Why do I even care? If it's not a SAS, the key combination could be hooked (likely by a non-privileged application) and someone could show a fake login dialog on which I would then enter my password.
So, is Win+L a secure attention sequence?
I have seen previously linked questions and
- How does CTRL-ALT-DEL to log in make Windows more secure? (ServerFault)
- some code from 2010 where it might have been possible to bypass the combination, but it does no longer work on Windows 10 20H2
- the flag LLKHF_INJECTED in KBDLLHOOKSTRUCT, which makes me believe that Windows can distinguish between physical and simulated keypresses, explaining why the code might not work any more
- I am aware of the Registry key
HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Policies\System, but that would affect Ctrl+Alt+Del as well