Azienda Trasporti Milanese

Azienda Trasporti Milanese, also known as ATM, is the public transport operator serving the city of Milan, Italy. It provides metro, bus and tram services that move residents and visitors throughout the metropolitan area. As the municipal transport company, its core function is to ensure the availability and reliability of urban mobility infrastructure.

The organisation has been involved in several notable cyber security incidents that highlight its exposure to digital threats. In March 2025, ATM disclosed that a breach at its app service provider Mooney Servizi SpA compromised users’ personal data stored in an archive hosted by WIIT SpA, prompting the company to request a security report, strengthen third‑party access controls and notify Italian data protection and cybersecurity authorities. In May 2023, the pro‑Russian hacktivist group NoName057(16) launched a Slow HTTP DDoS attack against the Milan Metro, causing an approximate two‑hour outage while the attackers reportedly used geolocking techniques. Earlier, in February 2019, hackers infiltrated ATM’s security systems, stole passwords, deployed malware that blocked legitimate access and targeted the subway camera software that manages turnstile and platform access data, an intrusion that required external cybersecurity expertise to investigate.

These incidents underscore ATM’s role as a critical infrastructure operator whose digital services and operational technology are attractive targets for cyber actors. The company’s responses—such as requesting detailed security reports from vendors, reinforcing controls for third‑party access and cooperating with national authorities—reflect its efforts to mitigate risks and improve resilience. While the prompt does not disclose quantitative details about the organisation’s size, workforce or annual ridership, the described events confirm its significance within Italy’s transport sector and its ongoing focus on safeguarding both customer information and operational systems.