A massive IT outage has knocked out Windows computers around the world, taking websites, airports and banks offline as engineers scramble to reboot their systems.
The problem began early on Friday morning UK time as workers found their PCs crashing, showing the so-called “blue screen of death” and entering recovery mode.
While companies across the globe struggle to get online, here is what we know so far about the problem.
What has happened and why is Windows down?
Hundreds of thousands of computers around the world have suddenly shut down, impacting businesses, transport links and TV broadcasts globally.
A software problem with a piece of cyber security technology, called Crowdstrike, appears to be to blame. The specific piece of technology, Crowdstrike Falcon Sensor, is used to protect against hacking threats, but engineers were quick to blame a problem with the system for causing the massive outage.
The issue mostly seems to be impacting PCs running on Microsoft’s Windows 10 software.
Who has been affected?
An awful lot of people. While we still do not know the full impact of the bug, so far this morning we have seen TV stations, transport links and banks complaining of problems.
Sky News was forced to pull its morning breakfast show and replace it with pre-recorded footage. Ryanair has warned on its website to expect major delays at airports around the world.
Images on social media showed computers across airports and transport hubs showing the notorious “blue screen of death”. Users also reported being stuck on airplanes on the runway.
The Gatwick Express warned commuters to expect short-notice cancellations across the train network.
Is it a cyber attack?
So far, all indications point to a software problem with Crowdstrike, but we know little about its root cause.
The technology is designed to protect computers against cyber incidents. As of 8am, Crowdstrike had issued no public update on the origin of the problem.
However, on a Reddit forum used by Crowdstrike engineers and cyber experts, users pointed to an update to customers which said: “CrowdStrike is aware of reports of crashes on Windows hosts related to the Falcon Sensor. Symptoms include hosts experiencing a bugcheckblue screen error related to the Falcon Sensor.”
What is Crowdstrike and who owns it?
Crowdstrike is one of the world’s largest cyber security technology companies – valued at over $80bn – whose tools are used by businesses around the planet.
Its typical technology is known as endpoint detection and response – a type of antivirus – used to deal with hacking threats.
These products are updated regularly to deal with potential new cyber treats and often automatically add new tools to your PC.
Troy Hunt, a cyber security expert, added in a post on X, formerly known as Twitter, that Crowdstrike’s tools often have “privileged” access on PCs, meaning they have broad control over the machines to try and remove threats.
However, he added that “also means that if something goes wrong with an update, it’s able to catastrophically nuke your machine”.
Crowdstrike the business is publicly listed in New York and owned by technology investors and major funds such as Blackrock.
Are the trains running today?
Network Rail has warned commuters to expect long delays and cancellations across the rail network this morning as train companies grapple with the impact of today’s IT crash.
In a post on National Rail’s website, it warned of a “network wide IT issue affecting a number of train operators services this morning”.
Avanti West Coast, Gatwick Express, Great Northern, Great Western Railway, Hull Trains, London Northwestern, Lumo, Northern, Southern, Thameslink, TransPennine and West Midlands were all affected.
⚠️ We are currently experiencing widespread IT issues across our entire network. Our IT teams are actively investigating to determine the root cause of the problem.
We are unable to access driver diagrams at certain locations, leading to potential short-notice cancellations,…
— Thameslink (@TLRailUK) July 19, 2024
“There are currently widespread IT issues across the entire network,” National Rail said. “IT teams are investigating to determine the root cause of the problem.
“As a result, some train operators are unable to access driver diagrams at certain locations, leading to potential short-notice train cancellations.
“Additional, other key systems including real-time customer information platforms, are also affected.”
Why was Sky News down?
This morning, Sky News viewers might have been expecting the morning’s breakfast show.
However, when people tuned in this morning, the typical broadcast was replaced with the error message: “We apologise for the interruption to this broadcast. We hope to restore the transmission of Sky News shortly.”
Presenter Jacquie Beltao said on Twitter: “We’re obviously not on air – we’re trying.”
Sky’s typical broadcast was replaced by a string of archive videos and pre-recorded news reports. The issue also hit other broadcasters around the world, including Sky’s international divisions, as well as ABC.