The online filing system used by the federal court system was likely breached in the SolarWinds hack, suspected to be orchestrated by Russia, potentially compromising highly sensitive sealed documents that contain nonpublic details about ongoing investigations.

The Administrative Office of the U.S. Courts revealed an “apparent compromise of the confidentiality” of its case management and electronic case files system “due to these discovered vulnerabilities” and said this week that it was “under investigation.” The federal judiciary is working with the Homeland Security Department on a “security audit” related to the cyberattacks that “greatly risk compromising highly sensitive non-public documents … particularly sealed filings” stored on the online system, adding that “due to the nature of the attacks, the review of this matter and its impact is ongoing.”