Why does Ctrl+Alt+Backspace work to log in to Windows on MacBook Pro?

Question

I have Windows 7 installed in Boot Camp on my 2011 MacBook Pro.

I have configured Windows to require a Ctrl+Alt+Del to log in. This is supposed to prevent malware from putting up a fake login screen.

The MacBook Pro does not have a "Del" key. Well, it does have a "delete" key, but that is equivalent to the "Backspace" key on a Windows keyboard. The MacBook Pro does not have a key equivalent to the "Del" key on a Windows keyboard. You have to press Fn+Delete on the MacBook Pro in order to simulate the Windows "Del" key.

When I press Ctrl+Alt+Fn+Delete on the Windows login screen, it works as it should. But I noticed that Ctrl+Alt+Delete works too, which really means that Ctrl+Alt+Backspace is working. That should not work (I tried it on another Windows PC with a Windows keyboard, and it does not work), and it makes me wonder if it might be a possible security hazard.

Answer 1

The key combination is a keyboard hook to call the trusted login process in windows but the apple driver in boot camp is sending that key combination that windows recognizes as the special key sequence and the actual keys used can be remapped. This is a apple article about the keyboard use in boot camp: http://support.apple.com/kb/HT1167 Note that in windows you can also remap those keys and use some other combination (assuming NT based windows).