Microsoft says 'no known ransomware' runs on Windows 10 S - so we tried to hack it
Found on ZDNet on Saturday, 24 June 2017

Microsoft claims "no known ransomware" runs on Windows 10 S, its newest, security-focused operating system.
It took him a little over three hours to bust the operating system's various layers of security, but he got there.
In the end, Microsoft said that "no known ransomware" works on the operating system, but by gaining "system"-level access, we showed that it's entirely possible to take control of the machine to install ransomware.
If someone promises 100% security, they are lying.