The Biden administration isn’t hesitating to blame China for a string of Microsoft Exchange cyberattacks. The White House has declared “with a high degree of confidence” that hackers linked to China’s Ministry of State Security (MSS) were responsible for a digital espionage campaign using the Exchange vulnerabilities. Officials have confronted senior Chinese leadership with this and “broader” hostile online activity, the White House said.

The US further accused China of running an intelligence operation that relied on “contract hackers” who frequently launched attacks meant solely for profit, such as ransomware schemes and crypto jacking. The Chinese government’s reported unwillingness to tackle these abuses is believed to hurt businesses, governments and infrastructure with “billions of dollars” in damage, the White House said.

Accordingly, the Justice Department has revealed indictments of four MSS-affiliated Chinese men for allegedly conducting an extended hacking campaign meant to steal intellectual property and trade secrets, including health research. The initiative, which ran between 2011 and 2018, reportedly saw Ding Xiaoyang, Cheng Qingmin, Zhu Yunmin and Wu Shurong compromise comptuers worldwide to grab information ranging from autonomous vehicle technology and chemical formulas through to research on Ebola, AIDS and other diseases.

Biden’s administration has already taken multiple actions in response to attacks, including “proactive network defense actions” like deleting backdoors on compromised Exchange servers. It added private companies to its Unified Coordination Group to bolster its security incident response. CISA, the FBI and the NSA also released an advisory outlining China’s strategy for compromising US and ally networks using the Exchange holes and other methods.

This comes on top of stricter security rules for pipeline companies as well as a pilot to tackle vulnerabilities in sectors like electricity and water supply.

China has historically denied involvement in attacks like these, and it’s doubtful the country will have a change of heart after this. The White House effort is more of a warning — the US will not only pin attacks on China, but respond to them in kind.