DHS confirms hackers breached HSIN info-sharing platform

The Department of Homeland Security is investigating a recent cyber intrusion that compromised the Homeland Security Information Network (HSIN) and a related SharePoint system; the attack, reported by Nextgov, occurred in late May–early June and targeted sensitive but unclassified information used for interagency coordination. DHS has isolated affected systems and launched a forensic investigation, with no confirmed attribution or evidence of stolen documents as of the report.