Chinese-based hackers have targeted the email accounts of high-ranking US officials, including Nicholas Burns, the US ambassador to China, and Daniel Kritenbrink, the assistant secretary of State for East Asia, in a cyber espionage campaign.

The attack, which is believed to be linked to a recent hack targeting federal agencies, has raised concerns about the security of sensitive information. The State Department has refused to disclose further details about the attack for security reasons. This incident follows a recent report by Microsoft, which revealed that Chinese hackers, known as Storm-0558, had gained unauthorized access to the email accounts of 25 organizations, including federal agencies, in order to gather intelligence.

The scale of this breach suggests that hundreds of thousands of individual US government emails may have been compromised. The US government is likely to respond with increased efforts to strengthen cyber security measures and protect against future attacks.