The US government confirmed on Wednesday that a cyberattack affected its networks and said the attack was "significant and ongoing", Reuters reports.
"This is a developing situation, and while we continue to work to understand the full extent of this campaign, we know this compromise has affected networks within the federal government," said a joint statement issued by the FBI, the Cybersecurity and Infrastructure Security Agency (CISA), and the Office of the Director of National Intelligence (ODNI).
"Over the course of the past several days, the FBI, CISA, and ODNI have become aware of a significant and ongoing cybersecurity campaign," the joint statement said.
The FBI, CISA and ODNI have formed a Cyber Unified Coordination Group to coordinate the US government's response, it added.
On Sunday, it was reported that a group of hackers backed by a “foreign government” stole information from the US Treasury Department and the Commerce Department’s National Telecommunications and Information Administration (NTIA).
Subsequently it was revealed that the attack also targeted the US Department of Homeland Security.
The Washington Post, citing people familiar with the matter, reported that Russian government hackers are responsible for the breach.
Robert O’Brien, President Donald Trump’s national security adviser, on Tuesday cut short a European trip in order to return to Washington to coordinate the government response to the hacking.