This guide explains how runtime security defends live Kubernetes workloads by monitoring system calls, network behavior, and file integrity. It shows why pre-deployment scans miss zero-day exploits and runtime threats like container escapes, lateral movement, and cryptomining. It then details how Cilium Tetragon uses eBPF in the Linux kernel for precise, real-time enforcement.

• Pre-deployment scans only catch known CVEs and miss zero-day kernel exploits or API-based code injection, so runtime monitoring of syscalls, network, and files is necessary to catch live attacks.
• Cilium Tetragon uses eBPF in the Linux kernel to enrich raw events with pod/namespace/deployment metadata (turning "PID 4052 ran bash" into "frontend pod in production ran bash") and can block or kill malicious processes in real time.
• Shared kernels and cgroups don't stop in-memory attacks or syscall abuse, and Kubernetes RBAC can't catch data-plane threats like lateral movement, cryptomining, or DNS-tunnel exfiltration.