Madison Elementary School District 38 (MESD) in Phoenix, Arizona, suffered a ransomware attack in April 2025 by the threat group Interlock, which exploited social engineering to breach the network. The attack exposed personal information of 35,000 individuals, including potential Social Security numbers and financial data, as suggested by the district’s offer of free identity protection services (IDX). Interlock claimed to have stolen 70 GB of data (49,000 files across 4,247 folders), including sensitive folders like Accounts Receivable, Gifts & Donations, and employee-related records. MESD engaged cybersecurity firm Arete for forensic analysis (costing ~$21,700) to assess the breach’s scope. While the district confirmed the attack, it did not disclose whether a ransom was demanded or paid. The incident marks one of the largest education-sector breaches in 2025, second only to Cherokee County School District’s attack (46,000 records). Interlock, active since October 2024, has targeted nine US educational institutions, with this attack highlighting vulnerabilities in school district cybersecurity defenses.