The reason of the outage is considered to be a buggy update of a cybersecurity vendor CrowdStrike. The update disconnects computers and servers from the network, forcing them into a recovery cycle that prevents the machines from booting properly.
However, Russian infrastructure is not largely affected by the outage.
Russian airlines long ago switched to a domestic booking system, and the global Microsoft outage did not affect them, Russian airline Red Wings said in a statement.
It was echoed by Moscow's Domodedovo airport, which stated that it was also not affected by the massive IT failure, and offered a backup check-in system, Astra, which is fully Russian, to its foreign partners.
Multiple companies worldwide suffered consequences of the outage. US-based United Airlines, Delta Air Lines, and American Airlines issued a global ground stop on all flights due to communication problems. Residents of Alaska, Arizona, Ohio, and other US states are unable to call emergency services due to a major local communications failure, local television reports.
Britain's largest rail operator, Govia Thameslink Railway, said it was registering disruptions and possible train cancelations. Indian airline IndiGo said on Friday that its services have also been affected.
"Our systems are currently impacted by a Microsoft outage, which is also affecting other companies. During this time, booking, check-in, access to your boarding pass, and some flights may be impacted. We appreciate your patience," Indigo said on X.
Germany's airline Lufthansa said on Friday there might be restrictions on access to profiles and bookings due to a technical glitch.
"Currently, the profile and booking retrieval functionality may be limited. We are working on a solution and apologize for any inconvenience caused," the airline said on its website.
The Australian government called an emergency meeting due to the global IT outage, local media reported.
Low-cost airline Jetstar Japan reported a glitch in its check-in system for domestic flights, resulting in flight cancelations and delays, the NHK broadcaster reported.