If you're using a Windows 10 machine, you might want to consider disabling Cortana — at least on the Lock Screen — if you aren't planning to install the latest Windows updates for whatever reason. (And, generally, do you really need a smart assistant helping you out when your PC is locked?)
Of course, someone would need physical access to a computer in order to perform the hack, but it would allow the person to launch files from a USB stick — and the sky's the limit after that.
McAfee recommends users run Windows Update to get Microsoft's latest security patch, which corrects the issue. However, if you aren't planning to, or need a bit of time before you can run the update, you can always just disable Cortana on your Lock Screen to circumvent the hack.
Screenshot: E.Price / Microsoft
To disable Cortana on the Lock Screen, launch the assistant by clicking on the circle icon to the left of the search bar on your taskbar. Click on the gear icon on the left pane, and then look for the "Lock Screen" section.
Untick the option to "Use Cortana even when my device is locked," which isn't the worst idea in the world anyway — even though Microsoft has patched the hack, do you want anyone to be able to chat with your desktop or laptop when you aren't using it?