When facing this issue, you can remedy by holding the power button for a while. The unit will shut down.
McAfee update needed
To avoid repeating or prevent the issue, a McAfee update is needed.
As soon as you are connected to the internet, the update will be automatically pushed to your computer within the 4 coming hours. Any version equal or above 12.8.856 contains the fix. The version can be checked in the VAIO menu, via Programs and Features.