Cybersecurity firm CrowdStrike has deployed a fix for an issue that triggered a major tech outage that affected industries ranging from airlines to banking to healthcare worldwide, the company’s CEO said on Friday.

Microsoft said separately it had fixed the underlying cause for the outage of its 365 apps and services including Teams and OneDrive, but residual impact was affecting some services.

“This is not a security incident or cyberattack. The issue has been identified, isolated and a fix has been deployed,” CrowdStrike CEO George Kurtz said in a post on social media platform X.

The issue stemmed from a defect found in a single content update for Microsoft Windows hosts, Kurtz said, adding Mac and Linux hosts were not impacted by the issue.

Shares of CrowdStrike tumbled nearly 12% in premarket trading, while Microsoft was down 1.4%.

A massive IT outage was disrupting operations at companies across multiple industries on Friday, with major airlines halting flights, some broadcasters off-air and sectors ranging from banking to healthcare hit by system problems.

“We’re deeply sorry for the impact that we’ve caused to customers, to travelers, to anyone affected by this, including our company,” Kurtz told NBC News’ “Today” program.

“Many of the customers are rebooting the system and it’s coming up and it’ll be operational,” Kurtz said. “It could be some time for some systems that won’t automatically recover.”

CrowdStrike’s “Falcon Sensor” software was causing Microsoft Windows to crash and display a blue screen, known informally as the “Blue Screen of Death,” according to an alert sent by CrowdStrike earlier to its clients and reviewed by Reuters.

The travel industry was among the hardest hit with airports around the world reporting delays and issues with their system network, while banks and financial institutions from Australia and India to South Africa warned clients about disruptions to their services. – Rappler.com