A defective update from cybersecurity firm CrowdStrike led to a massive global IT outage on July 19, impacting millions of Windows systems and causing significant disruptions across various sectors. The incident has been described as one of the most widespread IT failures in recent years. It affected computers running Microsoft Windows, with users reporting issues such as boot loops and “Blue Screen of Death” errors.

The faulty update, part of CrowdStrike’s Falcon sensor software, was intended to collect data on possible cyber threats. However, the update contained a defective channel file, leading to system crashes. This glitch brought down entire organizations, including airlines, banks, hospitals, and government services, creating chaos and operational delays worldwide.

CrowdStrike’s CEO George Kurtz confirmed the issue, stating that the company had identified the problem and rolled back the faulty update. He emphasized that the outage was not the result of a cyberattack but a technical defect. “CrowdStrike is actively working with customers to resolve the issue,” Kurtz said, advising users to communicate through official channels for support and updates.

The outage hit the travel sector particularly hard, causing flight delays and cancellations at airports globally, including major hubs in the United States, Europe, and Asia. In the US, the Federal Aviation Administration implemented a nationwide ground stop to assist airlines like American Airlines, United Airlines, and Delta Airlines in managing the crisis. Reports of disrupted services also came from airports in Berlin, Barcelona, Brisbane, Edinburgh, Amsterdam, and London.

Healthcare services were also significantly affected. Hospitals in the Netherlands, Spain, and the US reported system failures, impacting patient care and emergency services. The National Health Service (NHS) in the UK advised citizens to use emergency lines only for critical situations due to the strain on their systems.

Amid the chaos, the US Cybersecurity and Infrastructure Security Agency (CISA) warned of opportunistic phishing attacks exploiting the outage. Malicious actors have been sending emails impersonating CrowdStrike, attempting to deceive users into paying for fake fixes. CISA advised individuals to be vigilant and avoid clicking on suspicious links.

Despite CrowdStrike’s deployment of a fix, the recovery process is expected to be prolonged, particularly for large organizations with extensive IT infrastructures. The company has reported that out of the 8.5 million Windows devices that were impacted, a significant number are now back online and operational.