Businesses around the world have reported IT outages, including Windows “Blue Screen of Death” errors on their computers, making it one of the most widespread IT outages in recent years. The outage is linked to a software update from well-known cybersecurity firm CrowdStrike and has affected computers running Microsoft Windows at organizations across a range of sectors, including airlines, banks, retailers, brokerages, media companies and rail networks. Online rumors suggest that the travel industry is the hardest hit.
CrowdStrike CEO George Kurtz acknowledged in a post on X that a “flaw” in content updates for Windows hosts was the cause of the outage, denying the possibility of a cyberattack, adding that the company is rolling out a fix and that Mac and Linux hosts are not affected.
“CrowdStrike is actively working with customers affected by the flaw found in the single content update for Windows hosts. Mac and Linux hosts are not affected,” Kurtz said at X.
“This is not a security incident or cyber attack. The issue has been identified, isolated, and a fix is being deployed. We direct customers to our support portal for the latest updates, and will continue to provide complete and ongoing updates on our website. We also encourage organizations to get in touch with CrowdStrike representatives through official channels. Our team is committed to ensuring the security and stability of CrowdStrike customers,” Kurtz said.
A post on CrowdStrike's support forum (which can only be accessed by logging in) also acknowledged the issue early Friday, saying the company had received reports of crashes related to a content update. CrowdStrike said the crash reports were “related to Falcon Sensor,” the company's cloud-based security service that it describes as “real-time threat detection, simplified management and proactive threat hunting.”
Screenshot of CrowdStrike post. Image courtesy of CrowdStrike
A moderator on CrowdStrike's subreddit also said the company was aware of “widespread reports” of blue screen errors occurring on devices with multiple versions of Windows. The company was investigating the cause, the message said.
The security company did not immediately respond to a request for comment.
Microsoft began noticing the issues in the early hours of July 19. The company's service health page states that Microsoft 365 for Consumers has now been restored. However, enterprise apps are still experiencing disruptions, according to the service health status for the company's business cloud services.
“We're aware of an issue impacting Windows devices caused by a third-party software platform update. We expect a resolution is available soon,” a Microsoft spokesperson told TechCrunch in a statement.
A Microsoft spokesperson said the Microsoft 365 outage that occurred overnight on July 18-19 was not related to the widespread outage caused by the CrowdStrike update.
Many questions will be asked and answered, including the resilience (or lack thereof) of cloud services, and specifically how a single update could cause so many outages across the globe.
“We believe that because cybersecurity products are mission-critical and actively attacked by adversaries, they must meet higher reliability and security hurdles for customer adoption than other technology products,” Goldman Sachs analysts wrote in a research note on Friday. “In some ways, we believe this raises the barrier to entry into the industry and increases the need for best-in-class update, outage and customer service protocols, ultimately favoring larger firms.”
Airlines and airports in Germany, France, Netherlands, UK, US, Australia, China, Japan, India, Singapore and Taiwan have reported issues with check-in and ticketing systems, causing flight delays and airport confusion.
Federal airspace officials said Friday they were halting ground air traffic across the U.S. because of the power outage.
In Britain, the London Stock Exchange reported disruptions, and several British clinics said an outage had hit the National Health Service's clinical computer system, which stores medical records and is used to schedule appointments.
Some 911 and non-emergency call centers in the United States also appear to be affected, with many such call centers “not functioning properly across the state of Alaska,” according to a post from the Alaska State Police.
British news broadcaster Sky News suffered a disruption to its live broadcast this morning due to a power outage, the company's chairman David Rose tweeted. The New Zealand Herald reported that banking services in the country were also affected by the problem, and several news stations in India were also disrupted.
Employees at many companies have reported being unable to boot their computers due to the issue. The outage occurred shortly after Microsoft confirmed a service issue with Microsoft 365 apps late Thursday that affected several airlines, including Delta and United Airlines. Microsoft's service status page said the issue was being resolved.
Amid the confusion, misinformation has spread that the Las Vegas Sphere is displaying a blue screen of death.
Businesses and security experts began condemning CrowdStrike early Friday morning, before the company acknowledged its role in the incident. The company's software is used by millions of people across businesses to manage security for both devices and servers.
According to CrowdStrike's website, its customers include approximately 60 percent of the Fortune 500 and more than half of the Fortune 1,000. The company serves eight of the top 10 financial services companies and an equal number of leading technology companies. It also has a deep and broad presence in the healthcare and manufacturing sectors, serving six and seven of the top 10 companies in those industries, respectively.
CrowdStrike shares fell about 18% in premarket trading on Friday. CrowdStrike's market capitalization was $83.48 billion as of Thursday's market close.
Ram Iyer, Ingrid Lunden and Zack Whittaker contributed to this report.
A Microsoft/CrowdStrike outage has shut down most of India's airports. Today I received my handwritten boarding pass for the first time 😅 pic.twitter.com/xsdnq1Pgjr
— Akshay Kothari (@akothari) July 19, 2024
Prague Airport is currently affected by an outage of the global check-in system used by many airlines, resulting in delays to some departing flights. pic.twitter.com/fFpXkMccXO
— Prague Airport (@PragueAirport) July 19, 2024
Something very strange is happening right now. In the last few minutes I've been getting calls from several completely different outlets about Windows machines suddenly going into BSoD (Blue Screen of Death). Has anyone else seen this? It seems to go into recovery mode. pic.twitter.com/DxdLyA9BLA
— Troy Hunt (@troyhunt) July 19, 2024
This article was originally published on July 19 at 12:09 a.m. and has been updated to reflect new information.