In February 2015, US healthcare giant Anthem disclosed that it had fallen victim to a serious cyber-attack, one of the most serious against a US firm to date. Hackers gained entry to the network through a phishing email, then over a period of months, infiltrated secure data warehouses before ultimately compromising the data of over 78 million individuals.

Following years of investigations and amid speculation that a hack this sophisticated could only have been the work of a nation state, the US Department of Justice finally revealed an indictment of two of the hackers responsible: Wang Fujie and a second individual going by aliases including as “Deniel Jack,” “Kim Young” and “Zhou Zhihong.” The two are believed to be part of a sophisticated group also behind attempted attacks on three other data-rich US businesses.

This latest news comes in the context of increased attacks by China-based groups to break into US systems for commercial gain, targets of which include telecoms providers, hotel chains and big pharma. According to top cybersecurity firm CrowdStrike, the attacks are “likely to be tied to increased tensions between the two countries”.

Chinese attacks on US companies had slowed following the landmark 2015 deal by President Barack Obama and President Xi Jinping, which agreed to cease cybertheft of intellectual property. However, this progress seems to have been reversed amid rising tensions about trade. And in the meantime, the hackers have become stealthier and more sophisticated.

It’s not just China the US is worried about; attacks from Russian, Iranian and Korean hackers are also a present threat. These developments serve as further proof, if any was needed, of the importance of state-of-the-art cyber defences to protect against attacks from malicious actors, whatever their origin or motivation.