On Friday morning Asia time, Microsoft stated on its website that some users were unable to use its 365 applications and services. The United States was the first to experience problems, with Frontier Airlines suspending flights for more than two hours and attributing the cause to a Microsoft online service failure. In the afternoon, IT failures erupted globally from airlines and airports to the London Stock Exchange, McDonald's, Universal Studios Japan, cybersecurity company CrowdStrike, and more.
CrowdStrike stated that its Falcon Sensor threat monitoring product caused Microsoft Windows operating systems to crash. These issues occurred simultaneously with interruptions in Microsoft's Azure cloud and 365 office software services. Microsoft posted on social media that it had completed "mitigation actions" and that all Microsoft 365 applications and services had been restored, and the company is monitoring to ensure that the interruptions are fully resolved.
This global IT outage spread to Wall Street, where employees of banks such as JPMorgan, Nomura, and Bank of America were unable to log in to their company systems on Friday, and many of their screens turned blue with error messages. The US stock market was weak in early trading on Friday, and CrowdStrike's stock price fell as much as 15%, while Microsoft's fell 1.9%.