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falco(8)

Falco is a runtime security monitoring and detection engine that tracks system calls and kernel events to detect suspicious behavior and policy violations.

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Synopsis

falco [OPTIONS] [-o OUTPUT_FORMAT] [-D RULE_FILE]

Description

Falco monitors system-level activity by analyzing kernel syscalls and events in real-time. It compares observed behavior against a set of security rules to detect anomalies, intrusions, and policy violations. Falco can run as a daemon or in the foreground and outputs alerts when suspicious patterns match defined rules.

Common use cases include detecting unauthorized process execution, file access violations, network connections from unexpected sources, and privilege escalation attempts. Falco integrates with container platforms like Kubernetes and Docker to provide runtime security.

Common options

FlagWhat it does
-o, --outputOutput format for alerts: json, text, csv (default: json)
-D, --daemonRun Falco as a daemon in the background
-c, --configPath to the Falco configuration file
-r, --rulesPath to a specific rules file to load (can be used multiple times)
-l, --listList all loaded rules and exit
-p, --printPrint default rules to stdout and exit
-e, --eventsSpecify which events to capture (advanced filtering)
-k, --k8s-auditEnable Kubernetes audit logging integration
-v, --validate-rulesValidate rules syntax without running Falco
-M, --multiplierMultiplier for system call buffer size

Examples

Run Falco in the foreground with default rules, displaying alerts in real-time

sudo falco

Start Falco as a daemon using a custom configuration file

sudo falco -D -c /etc/falco/falco.yaml

Load a custom rules file and output alerts in JSON format

sudo falco -r /path/to/custom_rules.yaml -o json

List all loaded rules with their descriptions and conditions

sudo falco -l

Validate rules syntax without actually running the monitoring engine

sudo falco -v -r /etc/falco/rules.yaml

Run Falco and redirect CSV-formatted alerts to a file for analysis

sudo falco -c /etc/falco/falco.yaml -o csv > alerts.csv

Monitor Kubernetes audit logs using Falco rules specific to cluster events

sudo falco -k /etc/falco/rules/k8s_audit_rules.yaml

Related commands