There have been four major attacks on Airbus in the last 12 months, according to two security sources involved in investigating the hacking.
The group has long been considered a tempting target because of the cutting-edge technologies that have made it one of the world’s biggest commercial plane manufacturers, as well as a strategic military supplier.
In January, it admitted to a security incident that had “resulted in unauthorised access to data”, but people with knowledge of the attacks outlined a concerted and far bigger operation over the last year.