The UK is joining what it calls likeminded partners to confirm that Chinese state-backed actors were responsible for gaining access to computer networks around the world via Microsoft Exchange servers.
The attacks took place in early 2021, affecting over a quarter of a million servers worldwide.
The government says the attack was highly likely to enable large-scale espionage, including acquiring personally identifiable information and intellectual property.
At the time of the attack, the UK says it quickly provided advice and recommended actions to those affected and Microsoft said that by end of March that 92% of customers had patched against the vulnerability.
The UK is also attributing the Chinese Ministry of State Security as being behind activity known by cyber security experts as “APT40” and “APT31”.
Widespread, credible evidence demonstrates that sustained, irresponsible cyber activity emanating from China continues.
The Chinese government has ignored repeated calls to end its reckless campaign, instead allowing its state-backed actors to increase the scale of their attacks and act recklessly when caught.
This coordinated action today sees the international community once again urge the Chinese government to take responsibility for its actions and respect the democratic institutions, personal data and commercial interests of those with whom it seeks to partner.
The UK is calling on China to reaffirm the commitment made to the UK in 2015 and as part of the G20 not to conduct or support cyber-enabled theft of intellectual property of trade secrets.
As part of a cross-Government response, the National Cyber Security Centre (NCSC) issued tailored advice to over 70 affected organisations to enable them successfully to mitigate the effects of the compromise.
In 2018, the UK government and its allies revealed that elements of the Chinese Ministry of State Security (MSS) were responsible for one of the most significant and widespread cyber intrusions stealing trade secrets.
Foreign Secretary Dominic Raab said: “The cyber attack on Microsoft Exchange Server by Chinese state-backed groups was a reckless but familiar pattern of behaviour. The Chinese Government must end this systematic cyber sabotage and can expect to be held account if it does not.”