
Chinese state-sponsored hackers infiltrated the computer of US Treasury Secretary Janet Yellen, gaining access to unclassified files in a broader breach of the Treasury Department, sources familiar with the matter told Bloomberg News on Thursday.
The attackers also compromised the computers of Deputy Secretary Wally Adeyemo and Acting Under Secretary Brad Smith, the sources revealed. Fewer than 50 files were accessed on Yellen's machine, one source said.
A Treasury spokesperson, Chris Hayden, declined to comment on the incident.
This breach marks another significant cyberattack attributed to the Chinese government, targeting the upper echelons of a US federal department.
The hackers appeared to focus on Treasury’s operations related to sanctions, intelligence, and international affairs. However, classified systems and email servers remained secure, according to a Treasury report reviewed by Bloomberg News.
The Treasury Department briefed congressional aides and lawmakers on the incident during meetings on Capitol Hill, the report said. These discussions coincided with the Senate Finance Committee’s confirmation hearing for Scott Bessent, President-elect Donald Trump’s nominee for Treasury secretary.
Last month, the US Treasury Department alerted lawmakers to a cybersecurity breach involving a Chinese state-sponsored actor, marking what officials describe as a “major incident.”
Chinese officials have repeatedly denied involvement in state-sponsored cyberattacks. In response to the Treasury breach, a Foreign Ministry spokesperson dismissed the accusations as “unwarranted and groundless.”