NICT Warns of A2B Attacks Where Reverse-Engineered Android Apps Expose Vulnerable Backend Servers
Japan's National Institute of Information and Communications Technology (NICT) has issued an alert on A2B attacks, in which publicly available Android apps are reverse-engineered to identify and target their backend servers. The technique, called App-to-Backend Attack, allows threat actors to discover internal server endpoints even when organizations do not publish connection details. Once identified, attackers exploit vulnerabilities, weak authentication, or misconfigured APIs on those servers, leading to unauthorized access and data theft. NICT notes that multiple recent membership-service breaches in Japan stem from this vector rather than flaws in the mobile apps themselves. The institute urges developers and operators to harden backend infrastructure, conduct thorough compromise assessments, and apply proper access controls. Related incidents include unauthorized access to Lawson ID services, Yakiniku King app member data, and Japan Post's postal app.
Security NEXTOct 13, 2026Translated from Japanese