Alert queues are noisy by design. If your hunting program only follows what the SIEM bubbles up, you’ll mostly find what your tooling already knows how to see. Hypothesis-driven threat hunting flips that script: you start with an informed guess about adversary behavior, then design targeted tests to confirm or refute it. The result is less alert-chasing, more discovery—especially for low-and-slow activity that evades signatures.
What Is Hypothesis-Driven Hunting?
A hunt hypothesis is a concise statement that ties an actor (or class of actor) to a tactic/technique against a target in your environment, with an expected observable outcome. You use it to guide collection, queries, and pivots—then iterate based on what you learn. Let’s look at how that might look in practice.
Template:
We believe [actor or technique] is attempting [tactic/technique from ATT&CK] against [asset class/business process], which would produce [specific artifacts/behaviors] in [data sources]. We will confirm or refute by [queries/pivots], and we’ll call it closed when [decision criteria] are met.
Inputs That Make Hypotheses Strong
- Threat Intelligence: Actor TTPs, recent exploit usage, infrastructure patterns, targeting trends, and exploit maturity. Exclusive sources (e.g., dark-web telemetry, private actor tracking, high-fidelity passive DNS) sharpen the “who” and “how.”
- Environment Context: Where your crown jewels live, typical user/identity flows, third-party access, and internet-facing surfaces.
- Telemetry Coverage: Endpoint events, identity logs (SSO, MFA, OAuth), network flows, application/runtime logs, and cloud control plane activity.
A Practical Workflow (Repeatable Each Sprint)
- Frame the Hypotheis
- Example 1: “Finance-targeting crews favoring OAuth token theft (T1550.001) may be abusing legacy mail protocols to bypass MFA.”
- Example 2: “Actors reusing bulletproof VPS ranges we’ve seen in recent phishing may be staging data exfil over DNS (T1048).”
- Map to ATT&CK
Anchor on specific techniques/sub-techniques to avoid vague hunts and to reuse community knowledge. - Define Expected Artifacts
What would you see if the hypothesis were true? (e.g., anomalous IMAP logins, mailbox rules creation, rare nslookup bursts, long-lived processes spawning archivers). - Design Queries & Pivots
- Identity: impossible travel + legacy protocol logins from new ASNs
- Endpoint: script interpreters spawning network tools; unsigned processes touching credential stores
- Network: egress to rare ASNs/ports; TXT query bursts; consistent beacons with jitter
- Intelligence pivots: shared TLS certs, domain registrant patterns, VPS provider overlaps
- Run, Triage, and Tag
Investigate hits, tag true/false positives, and note gaps (e.g., missing telemetry on a subnet). - Decide & Document
Close as confirmed, refuted, or “informational.” Capture playbook steps, queries, artifacts, and outcomes for reuse. - Operationalize
Promote stable detections to content (rules, analytic stories), add enrichments, or tune controls. Feed gaps into your logging roadmap.
Example Hunt Snippets (Abbreviated Ideas)
- OAuth Abuse Hypothesis:
Signal mix: IMAP/POP logins from first-seen IPs + new app passwords + mailbox forwarding rules to external domains. - DNS Exfil Hypothesis:
Signal mix: High-entropy subdomain queries to a rare domain + periodicity + large TXT responses + process lineage showing archiving before spikes.
- Time-to-first-signal: From hypothesis to first high-confidence lead.
- Detection uplift: New detections/playbooks created from hunts.
- Gap burn-down: Telemetry or control gaps closed because a hunt exposed them.
- Repeatability: Percentage of hypotheses that become reusable procedures.
Common Pitfalls (and Fixes)
- Vague hypotheses → Anchor to ATT&CK techniques and concrete artifacts.
- Data sprawl → Start where impact and visibility intersect (identity, egress, and high-value apps).
- One-and-done hunts → Schedule re-runs when TI shifts (new PoC, fresh actor interest, infrastructure reuse)
- No closure criteria → Define what “confirmed,” “refuted,” and “needs follow-up” look like before you query.
Takeaways
Hypothesis-driven hunting transforms intel and telemetry into testable, repeatable investigations. By stating who might do what to which assets—and what you’d see if they did—your team uncovers stealthy activity earlier, converts insights into durable detections, and steadily raises the bar for adversaries.
Do you have the tools it takes to understand who is attacking your organization and why? Ultimately, it’s the only way to know how to stop attacks. Platform Blue offers government-grade threat intelligence to the worlds most elite threat hunting organizations. Get a demo today!