What caused the Microsoft IT outage that broke flights, banks and trains across the world?

What caused the Microsoft IT outage that broke
flights, banks and trains across the world?

A widespread computer outage left flights grounded, TV stations offline and much of the world’s infrastructure not working on Friday. 

Cyber security experts said the outage was “unprecedented” in its reach, affecting many of the world’s biggest companies. 

The cause of the problems was initially mysterious: Windows computers showed a blue screen of death, or BSOD, as if they had just spontaneously stopped working.

But as the outage has spread over Friday, the cause of the problems has become more clear.

By Andrew Griffin.

Full story at Yahoo News.