When President Barack Obama invited China to join the international law community, this is not what he had in mind.

The Permanent Court of Arbitration’s Web page for a high-profile arbitration related to the South China Sea was compromised this month, according to a cyberthreat research team that scans websites for vulnerability. The group, ThreatConnect, reports that it discovered a breach in PCA cybersecurity on July 9—which was day three of an important hearing in the geopolitically sensitive case.