The IT outage on Friday, caused by a faulty software update from CrowdStrike, has affected businesses and individuals around the world. The incident is another example of how a seemingly small technical change can have far-reaching consequences.

Companies are currently struggling with issues on PCs, servers, and other IT devices that use Microsoft Windows. Affected users are seeing the infamous "Blue Screen of Death," indicating that Windows could not be loaded.

Microsoft attributed the cause of the problem to a faulty software update from CrowdStrike. The Falcon software from CrowdStrike, which is designed to fend off cyberattacks, caused the outage. According to George Kurtz, CEO of CrowdStrike, a "defect in a single content update for Windows" was responsible. Devices with macOS and the open-source operating system Linux were not affected.

This is not a security incident or cyber attack," emphasized Kurtz. "The problem has been identified, isolated, and a solution has been provided.

CrowdStrike is one of the largest providers of endpoint security software, protecting connections between computer networks and remote devices. The affected devices include laptops, phones, servers, as well as POS terminals and ATMs that use Windows.

The IT outage affected airlines, banks, broadcasters, and healthcare providers from the USA to Europe, Australia, Japan, and India.

The global IT outage this morning is unprecedented in the scope and scale of the affected systems," said Harjinder Lallie, a cybersecurity expert at the University of Warwick.

Ian Batten, lecturer in computer science at the University of Birmingham, explained that security and virus scanning software, such as that from CrowdStrike, requires "deep and comprehensive permissions" in the system. This means that in case of problems, the system "halts" to protect itself.

Microsoft's Azure Cloud Computing Platform, which largely runs on Windows, also reported issues for its customers. The incident was further complicated by a previous, unrelated Azure outage in the USA on Thursday evening.

Microsoft announced on Friday that the previous issue had been resolved and services like Office Online and Teams were available again. However, the Azure status page continued to show problems related to the Falcon update.

CrowdStrike, founded in 2011 and based in Austin, Texas, is a leading provider of cloud security solutions, protecting critical infrastructure for some of the largest companies worldwide.

According to Gartner, CrowdStrike is the second-largest vendor in the global enterprise endpoint security market, second only to Microsoft. CrowdStrike's software is widely used because of its technical excellence.

The shares of CrowdStrike, which opened about 15 percent lower on Friday morning in New York, have more than doubled in the past year, bringing the company's market capitalization to $83.5 billion.

How long will it take for the problems to be fixed?

During CrowdStrike's statement that a "solution has been provided," it is unclear how long it will take to distribute this to the large number of affected customers and their devices. Kurtz said that many customers have restarted their systems and are back in operation, but it could still take "some time" for all systems to be restored.

Microsoft advised technicians that "up to 15" restarts might be required to resolve issues with Azure services.

The problems could take "days to weeks" to be fully resolved, said Vasileios Karagiannopoulos, a cybersecurity researcher at the University of Portsmouth. Kevin Beaumont, also a cybersecurity researcher, stated on social media that the recovery for CrowdStrike customers would be an "incredibly painful" process.