implementing-ebpf-security-monitoring

name	implementing-ebpf-security-monitoring
description	Implements eBPF-based security monitoring using Cilium Tetragon for real-time process execution tracking, network connection observability, file access auditing, and runtime enforcement. Covers TracingPolicy CRD authoring with kprobe/tracepoint hooks, in-kernel filtering via matchArgs/matchBinaries selectors, JSON event export, and integration with SIEM pipelines. Use when building kernel-level runtime security observability for Linux hosts or Kubernetes clusters.
domain	cybersecurity
subdomain	security-operations
tags	["implementing","ebpf","security","monitoring","tetragon","cilium","runtime","observability"]
version	1.0
author	mukul975
license	Apache-2.0
nist_ai_rmf	["MEASURE-2.7","MAP-5.1","MANAGE-2.4"]
atlas_techniques	["AML.T0070","AML.T0066","AML.T0082"]
nist_csf	["DE.CM-01","RS.MA-01","GV.OV-01","DE.AE-02"]

Implementing eBPF Security Monitoring

When to Use

• When deploying kernel-level runtime security monitoring on Linux hosts or Kubernetes clusters
• When you need sub-millisecond visibility into process execution, network connections, and file access
• When traditional userspace monitoring tools introduce unacceptable performance overhead
• When building detection pipelines that require in-kernel filtering before events reach userspace
• When enforcing runtime security policies (kill process, send signal) at the kernel level

Common Misconfigurations & Verification

• No BTF = silent no-load: Tetragon needs kernel BTF (/sys/kernel/btf/vmlinux) or a matching external BTF for kprobe arg typing. On older/stripped kernels (no CONFIG_DEBUG_INFO_BTF) probes fail to attach and you get zero kprobe events while process_exec still flows — masking the gap. Verify ls /sys/kernel/btf/vmlinux and check kubectl logs -n kube-system -l app.kubernetes.io/name=tetragon for attach errors.
• Ring-buffer/event drops under load: high event volume overflows the perf/ring buffer and Tetragon drops events — a coverage hole that looks like "nothing happened." Watch tetragon_*_events_total and missed/map_errors metrics, scope policies with in-kernel matchArgs/matchBinaries selectors (filter in-kernel, not in userspace), and avoid an unfiltered tcp_connect Post on a busy host.
• Probe coverage gaps: a syscall-name hook (sys_execve) can be bypassed by a different entry point or arch (compat/32-bit, execveat); matching on a fragile Postfix/Prefix string (e.g., xmrig) is trivially evaded by renaming the binary. Prefer hashes/paths and hook stable internal funcs (commit_creds, fd_install) over syscall names where possible.
• Namespaced policy scoping mistakes: a TracingPolicyNamespaced only applies to its namespace — host-level or other-namespace activity goes unmonitored if you assumed cluster-wide.
• Enforcement risk: a Sigkill action on a too-broad selector can kill legitimate processes — stage every enforcement policy in Post (observe) mode first and review events before switching to Sigkill.