PPIVTR-D

I. Identification

The model with the Detect chevron highlighted.
Figure 50
STARTS WHENTelemetry and reports flowing. Runs continuously.
DONE WHENAn event of interest raised with evidence references attached.

Identification covers alerting, detection and hunting. Alerting is what reaches you, detection is the engineered logic behind it, and hunting is what finds whatever neither one caught.

Only hunting moves time to detect. Alerting and detection both mean something else found it first, and you inherit whatever dwell time that cost.

Layer the methods, and map detection logic to MITRE ATT&CK so the rules survive a change of tooling. Final classification stays with an analyst, because no model knows about the migration that started on Monday.

MethodStrong onWeak on
SignatureKnown malware and patterns at machine speed, few false positivesNew variants, zero days, and any attacker who has read the signature
BehavioralMass encryption, off-hours access, living off the land, insider misuseDepends on a tuned baseline. One company-wide baseline hides anomalies.
Machine learningSubtle patterns, triage and prioritizationNo organizational context, so the final call stays with a person
HybridLayered coverage that survives tool changesCost and complexity of operating several platforms together

Spend hunting hours above the automation line, on the artifacts an adversary cannot cheaply swap out. Hashes and addresses burn on contact, and automation already covers them at machine speed.

The Pyramid of Pain, from hash values at the bottom through IP addresses, domain names, network and host artifacts, tools, to TTPs at the top, labelled trivial through tough.
Figure 52. The Pyramid of Pain, David Bianco, 2013.
LayerCost to changeWho chases it
TTPsToughAnalysts. Methods the adversary cannot abandon.
ToolsChallengingAnalysts, with detections built on tool behavior
Network and host artifactsAnnoyingAnalysts, on beaconing, process chains, lateral movement
Domain namesSimpleAutomation, with analysts pivoting from the hits
IP addressesEasyAutomation
Hash valuesTrivialAutomation. High confidence, short shelf life.
Watch out
  • A single baseline averaged across business units defines normal too broadly for anomalies to surface. Scope baselines per business unit or per function.
  • Hunt from a catalog, with a hypothesis, a named data source, and a cadence. Findings from unstructured hunting are hard to repeat and harder to defend.