The Pennsylvania state courts agency’s website was hit by a cyberattack that did not appear to compromise any data, but left some online systems disabled, officials said Sunday night.

The federal government’s lead cybersecurity agency, the U.S. Department of Homeland Security and the F.B.I. were investigating the attack, Chief Justice Debra Todd said in a statement.

She called it a “denial of service” cyberattack, using the federal government’s description for when attackers “flood the targeted host or network with traffic until the target cannot respond or simply crashes, preventing access for legitimate users.”

The courts agency, the Administrative Office of Pennsylvania Courts, did not immediately identify the attackers or a motive. The agency also didn’t say whether its cybersecurity measures worked as designed or whether the attackers demanded money or a ransom.

Among the disabled online systems were use of use of online docket sheets and an electronic case document filing portal.

The state’s courts remained open, Todd said.