The **DHS** has launched an investigation into a cyberattack impacting the **Homeland Security Information Network (HSIN)**, a vital platform for interagency and public-private information sharing. The incident, first reported by **Nextgov**, is believed to have occurred between late May and early June, perpetrated by an as-yet-unidentified threat actor. The **HSIN** is a cornerstone for coordinating safety and security operations, managing incidents, and exchanging critical information, including details on persons of interest and potential threats. The breach reportedly targeted **HSIN** servers and a **SharePoint** system used for collaborative efforts. ### Impact and Ongoing Investigation While the full scope of the compromise, including whether any documents were exfiltrated, remains under investigation, the incident sparks concern, especially with the United States currently hosting **World Cup** games. Such an attack could potentially expose sensitive security planning, interagency coordination, or response procedures. A **DHS** spokesperson confirmed the incident, stating, "The **Department of Homeland Security** is aware of a recent cyber incident involving a specific, unclassified legacy information sharing environment." They emphasized that immediate action was taken to isolate affected systems, mitigate vulnerabilities, and initiate a comprehensive forensic investigation. Crucially, the **DHS** confirmed that "there is no indication that classified networks were impacted, and the system remains operational for our partners."  ### A History of Vulnerabilities This isn't the first security incident to plague **HSIN**. In 2023, an access misconfiguration, attributed to a contractor's coding error, exposed restricted data within **HSIN-Intel**, the platform's intelligence section. This error inadvertently set access permissions to "everyone" instead of a limited group of authorized users, leading to the exposure of sensitive U.S. person data and other personally identifiable information to all **HSIN** users.