Key takeaway
Build a team process connecting the threat model, data, tests and daily monitoring, and maintain it as the environment changes.
Start from a threat model
Map application and infrastructure flows, possible entry paths and risk-based priorities. Attack trees and flow diagrams help identify observable behaviour and the available telemetry needed to examine it. A model does not prove complete coverage: record data gaps separately.
From threat hunting to a detection use case
Use incident reviews, threat hunts and intelligence to form testable hypotheses. Add authorized red-team exercises that simulate attacks and purple-team exercises where attack and defence teams test together. For each use case, record the hypothesis, required data and expected investigation outcome.
Detection-as-code workflow
Keep rules under version control with peer review and testing. Sigma describes detections for log events, while YARA describes textual and binary patterns in samples. These formats are not interchangeable: verify target-system compatibility and any required conversion.
Define the rule
Record the purpose, data assumptions and version.
Test examples
In an authorized test environment, validate syntax, expected triggering examples and ordinary non-triggering examples.
Review the change
Review results and compatibility with the target system with peers.
Deploy with monitoring
Approve rollout, observe alerts and keep a prior version available for rollback.
Operate and maintain the cycle
Assign a rule owner, review schedule, telemetry requirements, escalation path and retirement conditions. Update rules using analyst feedback, false alerts and changes in data sources. A successful test does not establish continued operational coverage.