A mass cyberattack on Russias air booking system Leonardo sparked flight delays among major carriers on Thursday.Russia's flagship airline Aeroflotsaid the denial-of-service attack resulted in delays of up to an hour for departures at Moscows Sheremetyevo International Airport.Aeroflots subsidiary Rossiya Airlines reported similar delays at Sheremetyevo,according to Interfax.Less than an hour after the cyberattack was reported, Russias defense and industrial conglomerate Rostecsaid it fully restored Leonardos functionality.However, localized problems persist despite the restoration, an anonymous source at an unidentified airline told Interfax.Rostecsaid the massive DDoS attack came from abroad without identifying the country of origin.The defense conglomeratesaid Leonardo has been subjected to dozens of large-scale and unprecedented cyberattacks in recent months.Its clear that a real cyber war is being waged against the country, whose goal is to damage Russias IT infrastructure and disrupt critical industries, Rostec said.