Multiple U.S. federal agencies were the target of a global cyberattack that exploits software vulnerability, CNN reported Thursday.

Eric Goldstein, the executive assistant director for cybersecurity at the Cybersecurity and Infrastructure Security Agency (CISA), said in a statement to CNN that his agency is “providing support to several federal agencies that have experienced intrusions” following the hackers’ exploitation of the vulnerable software.

“We are working urgently to understand impacts and ensure timely remediation,” Goldstein said, but he did not mention who is behind the hack.

This follows warnings from CISA Director Jen Easterly who said earlier this week that Chinese hackers are likely to disrupt U.S. critical infrastructure if a conflict were to arise between the two nations.

“Given the formidable nature of the threat from Chinese state actors, given the size of their capability, given how much resources and effort they’re putting into it, it’s going to be very, very difficult for us to prevent disruptions from happening,” Easterly said during an event hosted by the Aspen Institute.

Her comments come amid rising tensions between the U.S. and China which has also affected cyberspace. 

The Hill has reached out to CISA for comment.