RUSSIA’S main state airline Aeroflot was crippled by a “massive hack” today, grounding hundreds of flights.

Pro-Ukraine hackers have claimed responsibility for the chaotic airport disarray in Moscow.

It follows major disruption caused by Ukrainian military drones, which led to days of problems for travellers.

Hackers Silent Crow and Cyber Partisans BY, which are pro-Ukraine, have claimed joint responsibility for an attack.

They say they have been working to undermine the Russian airline’s computer systems “for one year”. 

Travel mayhem gripped Aeroflot hub Sheremetyevo airport in Moscow today.

Dozens, then hundreds, of flights were cancelled – with more expected.

A Silent Crow statement says: “Together with our colleagues from Cyber Partisans BY, we declare the successful completion of a prolonged and large-scale operation, as a result of which the internal IT infrastructure of Aeroflot Russian Airlines was completely compromised and destroyed.

“For a year we were inside their corporate network, methodically developing access, going deeper to the very core of the infrastructure.”

The hackers also said they back the democratic opposition in neighbouring Belarus – a close Russian ally. 

Aeroflot passengers were told: “Aeroflot Russia has announced changes to its schedule due to an information system failure.

“Some flights have been rescheduled or cancelled.

“Passengers on cancelled flights are eligible for refunds and rebooking on flights within the next 10 days.”

But there was further confusion for passengers, as the same message added: “Please note that the airport ticket offices are temporarily unable to issue refunds or rebook tickets.”

Passengers were ordered: “To avoid crowding, please leave Sheremetyevo Airport and reissue or refund your tickets through the call centre.

“Thank you for your understanding.”

On Telegram, the airline said: “As a result, schedule adjustments for some flights are expected, including delays and cancellations.”

Aeroflot has been hit by Western sanctions but has continued to operate since Putin’s brutal invasion of Ukraine. 

The claimed hackers also sent a sneering message to Russia’s FSB security service.

They said: “You are incapable of protecting even your key infrastructures.

“To all employees of the repressive apparatus — your digital security is insignificant, and you yourselves have long been under observation.

“In the near future, the publication of part of the obtained data will begin. “

“We did not just destroy the infrastructure — we left a trace. Glory to Ukraine! Long live Belarus!”

The hackers further claimed they managed to “obtain and download the full array of flight history databases”.

“Restoration will require, possibly, tens of millions of dollars. The damage is strategic,” they added.

There was no immediate independent verification of the damage caused to Aeroflot. 

Silent Crow earlier this year claimed to have hacked Rostelecom, Russia’s state communications giant.

The Kremlin made clear it was alarmed by the Aeroflot hacking, which was confirmed by the Russian prosecutor-general’s office. 

Putin’s spokesman Dmitry Peskov said the disruption to the airline was “quite alarming”. 

“The threat of hacking is a threat that remains for all large companies that provide services to the public,” he said.

“We will, of course, clarify the information and wait for the relevant explanations.”

A criminal case was launched into the hack.