Falco

Falco is an open-source, cloud-native runtime security and behavioral monitoring tool originally created by Sysdig and graduated under the Cloud Native Computing Foundation (CNCF) ecosystem. Operating at the Linux kernel level, Falco utilizes extended Berkeley Packet Filter (eBPF) technology and kernel modules to intercept and analyze real-time system call invocations across container workloads, Kubernetes nodes, and cloud infrastructure. By parsing kernel-level system calls into a flexible, human-readable rule engine, Falco detects unexpected application behavior, privilege escalation attempts, namespace modifications, unauthorized file system modifications, and anomalous outbound network connections as they occur. When an adversarial action or policy violation is identified, Falco immediately generates structured security alerts enriched with rich Kubernetes metadata, such as pod name, namespace, container ID, and image tags. These alerts can be routed through Falcosidekick into diverse downstream operational systems, including SIEM platforms, Slack, Prometheus, and serverless response workflows for automated container termination or network isolation. Falco serves as an indispensable runtime detection layer in modern DevSecOps architectures, providing organizations with deep, low-overhead behavioral visibility and security compliance verification across distributed microservices and containerized Kubernetes clusters.