What Is Falco?

Falco is an open-source cloud-native runtime security project created by Sysdig and now a CNCF graduated project. It monitors system calls from the kernel to detect anomalous activity and potential threats in real time. Falco uses a rules engine to identify suspicious behavior such as unexpected process execution, file access, network connections, and privilege escalation in containers and Kubernetes environments.

Why Falco Matters

Image scanning and admission control protect against known vulnerabilities at deployment time, but they cannot detect threats that occur at runtime, such as a compromised container executing a shell, accessing sensitive files, or making unexpected network connections. Falco fills this gap by monitoring what actually happens inside running containers and alerting when behavior deviates from expected patterns.

Teams that understand and adopt falco gain a significant operational advantage, reducing manual effort and improving the reliability and scalability of their infrastructure. As cloud-native adoption accelerates, familiarity with falco has become a core competency for DevOps engineers, platform teams, and site reliability engineers working in production Kubernetes and cloud environments.

How Falco Works

Falco runs on each Kubernetes node, either as a DaemonSet or through a kernel module, and intercepts system calls from all containers. It evaluates each system call against rules that define normal and suspicious behavior. When a rule triggers, Falco generates an alert with details about the event, the container, the pod, and Kubernetes metadata. Alerts can be sent to Slack, PagerDuty, Elasticsearch, or any destination through output plugins.

Understanding how falco fits into the broader cloud-native ecosystem is important for making informed architecture decisions. It works alongside other tools and practices in the DevOps and platform engineering space, and choosing the right combination depends on your team's specific requirements, scale, and operational maturity.

Key Features

System Call Monitoring

Intercepts kernel-level system calls to detect threats that application-level monitoring cannot see.

Rule Engine

A flexible rules language defines suspicious behavior, with community-maintained defaults covering common threats.

Kubernetes Context

Alerts include rich Kubernetes metadata like pod name, namespace, and container image for fast incident triage.

Real-Time Detection

Detects and alerts on threats as they happen, enabling rapid response before damage escalates.

Common Use Cases

Detecting when a container spawns an interactive shell, which could indicate a compromised workload.

Alerting when a pod reads sensitive files like /etc/shadow or Kubernetes service account tokens unexpectedly.

Monitoring for unexpected outbound network connections that could indicate data exfiltration.

Enforcing runtime security policies that detect containers running with unexpected privileges or capabilities.

How Obsium Helps

Obsium's DevOps and security team helps organizations implement and optimize falco as part of production-grade infrastructure. Whether you are adopting falco for the first time or looking to improve an existing implementation, our engineers bring hands-on experience across cloud platforms and Kubernetes environments. Learn more about our DevOps and security services →