Key points learned
A security software update from cybersecurity firm CrowdStrike (CRWD) caused an outage of Microsoft (MSFT) cloud service, disrupting airlines, banks and other businesses around the world on Friday.
The outage sent CrowdStrike shares down 18% in premarket trading, while Microsoft shares fell more than 2% as the tech giant said the cybersecurity firm's update to its Falcon software affected its Windows platforms.
“We are aware of an issue affecting Windows Client and Windows Server virtual machines running the CrowdStrike Falcon agent, which may experience a BSOD and stop working on reboot,” Microsoft said.
CrowdStrike CEO George Kurtz confirmed the cybersecurity firm's role in the outage, blaming a “flaw” in an update.
“CrowdStrike is actively working with customers affected by a flaw discovered in a single content update for Windows hosts,” Kurtz said in a post on X. “Mac and Linux hosts are not affected. This is not a security incident or cyberattack.
“The issue has been identified, isolated, and a fix has been deployed.”
Delta, United, American Airlines to stop operating
Flights by major U.S. airlines, including Delta Air Lines (DAL), United Airlines (UAL) and American Airlines (AAL), were grounded Friday morning in an attempt to resolve the issues.
“All Delta flights have been temporarily grounded while we work to resolve a technical issue with the vendor,” Delta said in a statement on its website. “Delta will notify any customers whose flights are affected via the Fly Delta app and text message.”
The London Stock Exchange was also hit.
The London Stock Exchange said it was also affected by the attack, with RNS, its corporate news service, down.
The London Stock Exchange said its RNS news service is currently experiencing a global technical issue with a third party, preventing news from being published. Technical teams are working to restore service, and there is no impact on securities trading or other services on the London Stock Exchange.
Update – This story has been updated with the latest news.