Hackers breached DHS information-sharing network, people familiar say

A recent intrusion of the Department of Homeland Security's Homeland Security Information Network (HSIN) by an unknown actor potentially exposed sensitive unclassified information shared across federal, state, local, tribal and private partners. DHS has isolated affected systems, initiated a forensic damage assessment, and confirmed there is no indication classified networks were impacted; the breach—believed to have occurred between late May and early June—targeted HSIN servers and a SharePoint collaboration system and could jeopardize coordination and security planning for large events.