This is a function of Intel's Active Management Technology (AMT).
It's not a bug, it's a feature!
I is activated in bios by default and configured to allow remote control in standby and off mode.
In the box there is no explanation how to configure this, not on paper and not on cd.
You have to disable AMT, here we go:
Enter bios with F2, navigate to Intel ME.
The default password is admin (case sensitive), you have to change that to a strong password before proceding.
Your password has to be 8 to 32 characters long and must have at least
one upper case character, one lower case character, one number, and a special character like !,@,#,$,%,^,&,*.
Important: If you are using a non U.S. keyboard remember that the U.S. keyboard layout is active when in bios!
Then go to IME configuration and change manageable feature from Intel AMT to none.
Hit ESC and exit bios saving changes, that's it.
More info here:
If someone already configured the IME and you can't enter it because you do not know the changed password
you may reset it by running the maintenance menu after changing the bios configuration jumper.
REMEMBER: The board must be disconnected from linepower while setting this jumper, otherwise it might be damaged.