Runtime Security (Falco)
Key Takeaways for AI & Readers
- Dynamic Threat Detection: Runtime security focuses on monitoring container behavior during execution to detect and respond to threats that static analysis misses.
- System Call Interception (Falco): Falco uses kernel-level mechanisms (eBPF) to intercept and analyze every system call, providing deep visibility into container activity.
- Rule-Based Anomaly Detection: It identifies "bad behavior" based on predefined YAML rules, such as writing to sensitive directories or executing shells within containers.
- Automated Response: Falco integrates with tools like Falco Sidekick to enable automated responses, including immediate termination of compromised pods, enhancing real-time security.
Static scanning (checking images for CVEs) isn't enough. You need to know what your containers are doing while they are running. Falco is the industry standard for runtime security.
1. Detecting Intrusion
Try triggering a shell in the simulation below. Notice how Falco immediately detects the system call.
Target Pod
📦
Simulate an attacker or developer opening a shell.
🔴 Falco Event Stream
Waiting for syscall events...
Falco monitors kernel system calls in real-time. It uses rules to identify abnormal behavior that standard log tools might miss.
2. How it works
Falco sits in the Linux Kernel (via eBPF or a kernel module). It intercepts every system call (syscall) made by every process in every container.
- A process opens a file: Falco sees it.
- A process makes a network connection: Falco sees it.
- A process executes a shell: Falco sees it.
3. The Rule Engine
Falco uses YAML-based rules to define "Bad Behavior".
- Rule: "Alert if a process in a container writes to
/etc." - Rule: "Alert if a container makes a connection to a known malicious IP."
4. Response (Falco Sidekick)
Falco only detects. To respond, you use Falco Sidekick.
- Detect: Falco sends an alert.
- Act: Sidekick triggers a Lambda function or K8s Job to instantly delete the compromised pod.