Application performance monitoring, or APM, is software that tracks how business applications and their supporting services are behaving. It typically measures response time, error rates, throughput, availability, and dependency health across servers, databases, APIs, and cloud services. By collecting this telemetry, APM tools help administrators see whether an application is slow, broken, or overloaded.
In cyber security, APM matters because it sits close to valuable operational data and privileged management functions. Attackers may target APM consoles, agents, or integrations to steal credentials, hide outages, tamper with alerts, or use the platform as a foothold into broader infrastructure. Defenders rely on APM to detect suspicious performance drops, unauthorized configuration changes, and unusual service behavior. When combined with logs and incident response workflows, APM can provide early warning that an attack is affecting business services.