Cybersecurity giant CrowdStrike confirmed the issue came from a “defect” in a content update for its Microsoft Windows users, resulting in flights being grounded, health care services affected and online payment systems shut down.
Here is a closer look at what we know about the incident.
What exactly has happened?
The chief executive of CrowdStrike, George Kurtz, confirmed the issue was caused by a “defect in a single content update for Windows hosts” – in short, a flaw in a software update pushed out to customers using Windows PCs.
CrowdStrike is one of the world’s largest cybersecurity providers, providing antivirus and cyberattack prevention tools to businesses.
The flaw in its update caused many Windows PCs to crash, with many displaying the so-called “blue screen of death” and becoming unusable.
IT infrastructure at businesses and institutions around the world collapsed, taking many businesses and their online services offline.
This has particularly impacted the transport, financial and healthcare sectors, with airlines and airports, train services, pharmacies and GP surgeries and even the London Stock Exchange affected.
What is the scale of the impact?
The outage was “causing disruption in the majority of GP practices” in England.
The health service said patients should attend appointments unless told otherwise and should only contact their GP in urgent cases.
The National Pharmacy Association said “services in community pharmacies, including the accessing of prescriptions from GPs and medicine deliveries, are disrupted today”.
Sky News was briefly knocked off air and was then broadcasting at a reduced capacity, while many retailers reported issues with taking digital payments, with banks and the London Stock Exchange also reporting issues, although trading has continued.
At airports around the world, airlines reported being unable to process passengers and resorted to manually checking in customers. Some recommended passengers should not attempt to check in bags, and large queues formed at airports across the UK.
Train services were also disrupted with ticketing services at some stations impacted.
How has CrowdStrike responded?
Mr Kurtz said the company was “actively working” with those impacted.
He confirmed the outage was not a “security incident or cyberattack” and that the issue had been “identified” and “isolated” and a “fix has been deployed”.
The cybersecurity firm urged customers to check CrowdStrike’s support portal for updates and assistance.
Mr Kurtz added that his team was “fully mobilised to ensure the security and stability of CrowdStrike customers”.
How long will the issue take to be rectified?
Given the scale of devices and businesses impacted, it could take several days for every impacted computer to be fixed and returned to normal use, particularly at smaller firms with fewer resources.
Cybersecurity experts said it is good news that the issue has only impacted Windows users – CrowdStrike confirmed Apple Mac and Linux users were unaffected – and a fix having been deployed should mean larger IT departments can quickly begin restoring services.
But signs of disruption are likely to remain throughout Friday and into the weekend.