05.10.2025

Secure Your Cloud Native Apps with Falco: Real-Time Threat Detection

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Runtime security remains a critical challenge for SRE and platform teams managing Kubernetes clusters and containerized workloads. Traditional perimeter defenses fail to catch threats that emerge during execution. Falco addresses this gap by continuously monitoring kernel syscalls and container activity to alert on suspicious behavior the moment it occurs.

What is Falco?

Falco is an open-source cloud native runtime security tool for Linux systems. Originally developed by Sysdig and now a graduated project under the Cloud Native Computing Foundation, Falco observes kernel-level events like syscalls and enriches them with metadata from container runtimes and Kubernetes. It applies customizable rules to detect anomalies—unauthorized file access, privilege escalation, unexpected network connections—then forwards alerts to SIEM platforms or data lakes.

Key Features

Kernel-Level Monitoring: Captures syscalls via eBPF or kernel modules for comprehensive visibility into process activity.
Container & Kubernetes Awareness: Automatically correlates events with pod names, namespaces, and container IDs for context-rich alerts.
Custom Detection Rules: Ships with prebuilt rulesets for common attack patterns; extend or override rules to match your environment.
Flexible Alerting: Sends events to logging systems, Slack, or SIEM tools for centralized incident response.
Multi-Architecture Support: Runs on x86_64 and aarch64 architectures.

Installation

Install Falco on a Linux host using the official package repository:

curl -fsSL https://falco.org/repo/falcosecurity-packages.asc | \
  sudo gpg --dearmor -o /usr/share/keyrings/falco-archive-keyring.gpg

echo "deb [signed-by=/usr/share/keyrings/falco-archive-keyring.gpg] \
  https://download.falco.org/packages/deb stable main" | \
  sudo tee /etc/apt/sources.list.d/falcosecurity.list

sudo apt update && sudo apt install -y falco

For Kubernetes deployments, use the official Helm chart:

helm repo add falcosecurity https://falcosecurity.github.io/charts
helm install falco falcosecurity/falco --namespace falco --create-namespace

Usage

Start Falco as a systemd service or run it directly:

sudo systemctl start falco

Falco loads default rules from /etc/falco/falco_rules.yaml. When a rule triggers—such as detecting a shell spawned inside a container—Falco writes an alert to syslog or stdout:

Warning Sensitive file opened for reading by non-trusted program (user=root \
  command=cat /etc/shadow file=/etc/shadow parent=bash container_id=a3b4c5d6)

Customize rules by editing /etc/falco/falco_rules.local.yaml to tune sensitivity or add environment-specific detections.

Operational Tips

Tune False Positives: Review initial alerts and exclude known-good processes from triggering rules to reduce noise.
Integrate with SIEM: Configure Falco outputs to ship JSON events to Elasticsearch, Splunk, or Datadog for centralized monitoring.
Leverage Plugins: Extend Falco with official plugins for cloud provider audit logs (AWS CloudTrail, GCP Audit Logs) to correlate infrastructure and runtime events.
Deploy as DaemonSet: In Kubernetes, run Falco as a DaemonSet to monitor every node without manually configuring individual hosts.

Conclusion

Falco delivers real-time visibility into runtime behavior, empowering SRE teams to detect and respond to threats before they escalate. Its kernel-level monitoring and cloud native integrations make it essential for securing modern containerized workloads.

For efficient incident management and to prevent on-call burnout, consider using Akmatori. Akmatori automates incident response, reduces downtime, and simplifies troubleshooting.

Additionally, for reliable virtual machines and bare metal servers worldwide, check out Gcore.

Akmatori team