CrowdStrike announced that “a significant number” of devices affected by a global IT outage on Friday are now online. The firm, responsible for the faulty security update that caused widespread crashes of Microsoft Windows computers, is focused on fully restoring all systems.

The incident, described as one of the worst IT outages ever, impacted 8.5 million computers globally, affecting businesses, banks, hospitals, and airlines, with some still facing issues.

Read more: Global Services Are Slowly Rebounding After a Bug Caused Widespread IT Disruptions

CrowdStrike expressed gratitude to its customers and partners for their efforts during the disruption and apologized for the inconvenience.

The company is implementing a new fix to expedite system recovery but did not specify how many devices remain affected.

The outage led to the cancellation of over 1,400 US flights and disrupted health services in Britain, Israel, and Germany. The incident highlighted the vulnerability of global computer networks, emphasizing how a single error can have widespread repercussions.

Despite being a leading cybersecurity firm with 29,000 global customers, CrowdStrike was less utilized in China, which remained largely unaffected.