Building a Detection Foundation: Part 1 – The Single-Source Problem

Source: TrustedSec

Author: Carlos Perez

URL: https://trustedsec.com/blog/building-a-detection-foundation-part-1-the-single-source-problem

ONE SENTENCE SUMMARY:

Incident response experience reveals a recurring pattern: organizations overtrust “telemetry” that proves incomplete, misleading, and insufficient under pressure.

MAIN POINTS:

1. Field observations from incident response highlight consistent failures in security visibility.
2. Tabletop exercises repeatedly expose gaps between perceived and actual monitoring coverage.
3. Collected telemetry often looks comprehensive until real attackers stress it.
4. Hidden assumptions about logging create blind spots during investigations.
5. Detection confidence frequently exceeds evidence quality and completeness.
6. Operational reality shows some critical events are never captured or retained.
7. Response teams commonly discover missing context when reconstructing timelines.
8. Measurement of security posture is skewed by unvalidated data sources.
9. Overreliance on dashboards can mask telemetry brittleness and collection failures.
10. Patterns across cases suggest telemetry programs need continuous verification, not faith.

TAKEAWAYS:

1. Validate monitoring with realistic exercises rather than trusting tool outputs.
2. Prioritize completeness, integrity, and retention of logs for investigatory usefulness.
3. Challenge assumptions about what is actually being captured across environments.
4. Use incident learnings to iteratively harden telemetry collection and coverage.
5. Treat visibility as an engineering problem requiring testing, maintenance, and accountability.