They work in high-tech bunkers. Thousands of young people tapping keyboards and infiltrating networks oceans away to sift for secrets they aren’t supposed to have. They work on behalf of the Chinese government, on a quest to push its tentacles into as much of the world as it can.

The group known as APT40 is just one part of this large-scale hacking machine. But this part of the organisation is now a lot more high-profile thanks to a decision this week by the Australian government and others to publicise what they say is its involvement in significant hacking in the Australia.