Global IT outage knocks retailers, airlines, banks and others offline

Businesses and institutions around the world have been been knocked offline after a major IT outage, believed to have been caused by a faulty update to widely used cybersecurity software.

Supermarkets and other major institutions have reported computer issues disrupting services, while many businesses have been left unable to take digital payments.

In the UK, Sky News went off air, while Britain’s biggest train company warned passengers to expect disruption because of "widespread IT issues", as did many major airlines and airports.

Across England, GP surgeries have reported being unable to book appointments or access patient records as their EMIS Web system went down, while the National Pharmacy Association also said "services in community pharmacies, including the accessing of prescriptions from GPs and medicine deliveries, are disrupted today".

Microsoft said it was aware of and fixing issues with its cloud platform, Azure, but many cybersecurity experts have reported the potential source of the issue as CrowdStrike, which provides cyber attack monitoring and protection to many major businesses.

Experts have said a flawed update to the global cybersecurity firm's Falcon Sensor software could be the source of the problem.

CrowdStrike has not issued a statement on the issue, but calls to the company’s technical support phoneline were met with a recorded message that said it was "aware of reports of crashes on Windows … relating to the Falcon sensor". It has advised affected customers to log on to their customer service portal for assistance.

Overnight, Microsoft confirmed it was investigating an issue with its services and apps, with the tech giant’s service health website warning of "service degradation" that meant users may not be able to access many of the company’s most popular services, used by millions of businesses and people around the world.

Cybersecurity expert Troy Hunt also reported seeing issues at CrowdStrike, with Australian telecoms firm Telstra posting to X, formerly Twitter, that the worldwide outage was "because of a global issue affecting both Microsoft and CrowdStrike".

Cybersecurity experts said that the widespread access CrowdStrike’s Falcon Sensor had to business systems meant an issue with the platform would have widespread effects.

Toby Murray, Associate Professor in the School of Computing and Information Systems at the University of Melbourne, said: "CrowdStrike Falcon has been linked to this widespread outage. CrowdStrike is a global cybersecurity and threat intelligence company.

"Falcon is what is known as an Endpoint Detection and Response (EDR) platform, which monitors the computers that it is installed on to detect intrusions – hacks – and respond to them. That means that Falcon is a pretty privileged piece of software in that it is able to influence how the computers it is installed on behave.

"For example, if it detects that a computer is infected with malware that is causing the computer to communicate with an attacker, then Falcon could conceivably block that communication from occurring. If Falcon is suffering a malfunction then it could be causing a widespread outage for two reasons – one: Falcon is widely deployed on many computers, and two: because of Falcon’s privileged nature.

"Falcon is a bit like anti-virus software: it is regularly updated with information about the latest online threats – so it can better detect them. We have certainly seen anti-virus updates in the past causing problems e.g. here.

"It is possible that today’s outage may have been caused by a buggy update to Falcon."