My job is to constantly think about cyber attacks — this is the first time I've been truly alarmed

I’ve spent nearly every moment of the past few years thinking about how to stop cyber attacks. And this is the first time I’ve been truly alarmed. Friday’s ransomware attacks that infected over 150 countries — most notably shutting down hospitals all over England — proved that a cyber attack can determine whether someone lives or dies.

Read more from malware researcher Amanda Rousseau on the significance of WannaCry on Business Insider.