Microsoft says early June disruptions to Outlook, cloud platform, were cyberattacks

In early June, sporadic but serious service disruptions plagued Microsoft’s flagship office suite – including the Outlook email and OneDrive file-sharing apps – and cloud computing platform. A shadowy hacktivist group claimed responsibility, saying it flooded the sites with junk traffic in distributed denial-of-service attacks.

Initially reticent to name the cause, Microsoft has now disclosed that DDoS attacks by the murky upstart were indeed to blame.