Why NDR Beats Alerts in the Mythos Era: Bejtlich's Case for Network Interdiction

Despite the growing abundance of security telemetry, most SOC teams still struggle with fundamental questions during incident investigation: What actually happened? What evidence supports the conclusion? How do we know we have full context? According to Richard Bejtlich, author of NDR Essentials: A Practical Guide to Network Detection and Response, published in partnership with Corelight, answering these questions requires moving beyond the alert-driven triage model that dominates most security operations today.

Bejtlich argues that we have entered the “Mythos Era,” a period defined by the accelerated discovery of vulnerabilities that outpaces the investigative capacity of most organizations. Even with increased automation, SecOps teams are drowning in raw telemetry without validated evidence of active exploitation. As AI simultaneously accelerates both offensive and defensive capabilities, defenders must shift their focus from prevention alone to interdiction—the active identification and disruption of malicious activity between initial compromise and full breach. Preventative controls, Bejtlich notes, are insufficient: stolen credentials still authenticate, perimeter defenses still miss malware, and sensitive data still exfiltrates. A resilient program must invest in the ability to isolate and contain attackers mid-attack, a task that demands deeper network visibility than port scanning and perimeter monitoring alone can provide.

NDR is the practical answer to this challenge. The guide outlines four primary sources of network evidence—full packet captures, extracted files, transaction logs, and enriched alerts and detections—that together give practitioners the situational awareness required for active intervention. Modern NDR platforms function as interdiction engines, not passive barriers, enabling teams to validate findings, understand adversary behavior, and halt suspicious traffic before it propagates. For organizations seeking to harden their infrastructure, pairing NDR with complementary checks like an SSL/TLS configuration audit and a broader privacy checkup creates a layered foundation for evidence-driven threat hunting and AI-assisted investigations.