Cybersecurity and Infrastructure Security Agency (CISA) Director Jen Easterly testifies before a House Homeland Security Subcommittee, at the Rayburn House Office Building on April 28, 2022 in Washington, DC. 

Several U.S. agencies have been hacked as part of a broader cyberattack that has hit dozens of companies and organizations in recent weeks through a previously unknown vulnerability in popular file sharing software.

The Cybersecurity and Infrastructure Security Agency, the country's top civilian cybersecurity watchdog, said Thursday that it is still investigating the scope of the hacks, according to Eric Goldstein, its executive assistant director.