The Muséum national d'Histoire naturelle (MNHN) in Paris suffered a massive ransomware attack in late July 2025, crippling its internal network and disrupting critical operations. The attack forced the cancellation of the high-profile Tropical Autumn: Palms, Treasures and Secrets exhibition, a major seasonal event expected to draw significant public interest. Beyond cultural losses, the breach paralyzed research activities—600 scientists faced delays, with some losing €30,000–50,000 in unspendable research funds due to inaccessible systems. Digital tools for libraries, collections, and expertise were rendered unusable, halting parts of French natural science research. While public-facing sites (galleries, zoos, gardens) remained open, digitally dependent services (e.g., themed tours) were suspended. The institution filed a complaint, refusing ransom payments, and prioritized system restoration. The attack underscores the growing vulnerability of cultural institutions to cyber threats, with 40 French museums targeted similarly in the past year. Recovery efforts focus on securing infrastructure, but the financial, operational, and reputational damage persists.