On 19 July 2024, American cybersecurity company CrowdStrike distributed a faulty update to its Falcon Sensor security software that caused widespread problems with Microsoft Windows computers running the software. As a result, roughly 8.5 million systems crashed and were unable to properly restart[ 1] in what has been called the largest outage in the history of information technology[ 2] and "historic in scale".[ 3]
The outage disrupted daily life, businesses, and governments around the world. Many industries were affected—airlines, airports, banks, hotels, hospitals, manufacturing, stock markets, broadcasting, gas stations, retail stores, and more—as were governmental services, such as emergency services and websites.[ 4] [ 5] The worldwide financial damage has been estimated to be at least US$10 billion.[ 6]
Within hours, the error was discovered and a fix was released,[ 7] but because many affected computers had to be fixed manually,[ 8] outages continued to linger on many services.[ 9] [ 10]