What tools do threat hunters use?
Threat hunters usually work across a stack of tools rather than one, and the stack falls into a few categories. The center of it is a SIEM (Security Information and Event Management system) or security data lake, such as Splunk, Microsoft Sentinel, or Elastic, where most of the log data lives and where most hunting queries actually run. Around that sits EDR (Endpoint Detection and Response), such as CrowdStrike, SentinelOne, or Microsoft Defender, for process and host telemetry. Network and NDR (Network Detection and Response) tooling like Zeek and Corelight give the hunter visibility into traffic and connections. Threat intelligence platforms feed in indicators and actor context. Then there's the analysis layer, Jupyter notebooks for ad-hoc data work, Sigma for portable detection logic, and YARA for pattern matching against files.
A single hunt often touches several of these at once, because the evidence for one hypothesis is usually spread across endpoint, network, and identity logs. That's part of why hunting is slow. Simbian's AI Threat Hunt Agent sits above this stack as the reasoning layer. It queries these tools in place, correlates what comes back, and returns a verdict, so the hunter directs the hunt instead of operating each console by hand.
What are the best open-source threat hunting tools?
There isn't one best open-source tool, since threat hunting spans several jobs and the open-source options are strongest in different ones. A neutral rundown of the commonly used projects:
| Tool | Category | What it does |
|---|---|---|
| Wazuh | Open XDR / SIEM | Collects and correlates host and log data, alerting on rules |
| Zeek | Network analysis | Turns raw traffic into structured connection and protocol logs |
| Security Onion | Bundled distro | Packages Zeek, Suricata, and Elastic into one hunting-ready platform |
| Velociraptor | Endpoint DFIR / hunting | Queries endpoints live for artifacts and hunt indicators |
| YARA | Pattern matching | Matches files and memory against author-written signatures |
| Sigma | Detection rules | A portable rule format that converts to many SIEM query languages |
| MITRE ATT&CK Navigator | Coverage mapping | Maps techniques you can hunt for against your detection coverage |
These tools are good, and a lot of mature hunting programs run on them. It's worth being clear on where they stop, though. They collect data and match patterns you tell them to look for. The reasoning, forming the hypothesis, deciding which sources to pull, and judging whether a hit is a real threat or a benign explanation, is still on the hunter. Open-source tools shorten the data-gathering step; they don't remove the manual validation step, which is usually the part that eats the hours.
Can you use a SIEM for threat hunting?
Yes, and in most organizations the SIEM is where hunting actually happens. Platforms such as Splunk, Microsoft Sentinel, and Elastic hold the log data a hunt needs, and their query languages (SPL for Splunk, KQL for Sentinel) are built to slice that data across time. So the SIEM is a genuine hunting surface, not just a storage layer.
The catch is that a SIEM is query-driven and analyst-bound. You only find what you write a query for, which means every hunt is limited by the questions the analyst thought to ask and had time to ask. Writing good queries takes skill, and interpreting the results takes more of it. A single hypothesis can take hours of sifting across several searches before it's confirmed or ruled out, so teams end up testing a handful of hypotheses instead of dozens.
Simbian's AI Threat Hunt Agent works on top of the SIEM rather than replacing it. The agent queries Sentinel or Splunk natively, reads the results, and reasons about them, so the SIEM stays the data layer and the query-writing and interpretation are automated. No data migration; the logs stay where they are.
How do you evaluate a threat hunting tool or platform?
The useful criteria for evaluating a threat hunting tool are less about feature counts and more about how much of the actual hunt the tool takes off the analyst's desk. A few dimensions that tend to separate tools in practice:
- Automation depth. Does the tool just collect and surface data, or does it validate the hypothesis end to end and return a verdict? Many tools stop at "here's a faster query interface," which leaves the hard part with the hunter.
- Data federation. Can it reason across your existing sources, SIEM, EDR, identity, cloud, network, or does it only see one of them? Evidence for a single hypothesis is usually spread across several.
- Explainable evidence chain. When the tool reaches a conclusion, can a human replay every query it ran and audit how it got there? A verdict you can't verify isn't worth much.
- Rip-and-replace versus layering. Does it require centralizing your logs into a new platform, or does it query what you already have in place?
- Analyst-workload impact. After deployment, does the team spend less time on manual validation, or has the tool just added another console to babysit?
Cost matters too, but the tool that surfaces data without validating it usually costs more in analyst hours than it saves in license fees.
What should you look for in an AI threat hunting tool?
The main thing to look for in an AI threat hunting tool is whether it validates a hypothesis end to end or just collects and surfaces data faster. A lot of "AI hunting" is a better query interface, the analyst still has to interpret the output and decide what it means. That's a real convenience, but the validation bottleneck is still there.
Beyond full validation, a few things worth checking:
- Execution-log auditability. Can a human download and replay every query the agent ran, in order, to check the reasoning for hallucinations? If you can't audit it, you're trusting a verdict blindly.
- Benign-explanation testing. Before the tool calls something a threat, does it actively test the innocent explanations and show which ones it ruled out? An AI that only shows its conclusion, not its rejected alternatives, is harder to trust.
- Org-specific context. Does it apply knowledge of your environment, known assets, normal behavior, past findings, or run generic threat intel against generic logs? Context is what keeps false positives down.
- Native querying, no migration. Does it query your existing Sentinel, Splunk, or connected EDR in place, or does it want you to copy your data somewhere new first?
Splunk vs Microsoft Sentinel vs Elastic for threat hunting — how do they compare?
Splunk, Microsoft Sentinel, and Elastic are the three data platforms most hunting programs end up on, and they trade off along fairly predictable lines. Here is a neutral comparison of where each tends to fit:
| Dimension | Splunk | Microsoft Sentinel | Elastic |
|---|---|---|---|
| Query language | SPL, mature and very powerful | KQL, clean, strong for Azure/M365 data | Elasticsearch DSL / ES|QL |
| Strength | Deep, flexible search over almost any data | Cloud-native, tight Microsoft and Azure integration | Flexible and cost-effective, open ecosystem |
| Deployment | On-prem or cloud | Cloud-native (Azure) | Self-managed or Elastic Cloud |
| Trade-off | Can get expensive at high data volume | Best value inside a Microsoft-heavy shop | More assembly and tuning required yourself |
| Best fit | Teams that want maximum search power | M365 E5 / Sentinel data-lake customers | Teams wanting flexibility and lower cost |
None of the three is the wrong choice on its own. The right one usually comes down to what data you already have, what you already pay for, and whether your environment is Microsoft-centric.
Simbian's AI Threat Hunt Agent runs as the automation layer above any of these, not as a replacement for your data platform. The agent queries Splunk, Sentinel, or Elastic natively, so the platform you already chose stays the data layer and the reasoning runs on top.
What threat hunting queries should you start with?
If you're building a starter set of hunts, the highest-value queries look for behavior that attackers reliably produce but that rarely fires a clean alert. A practical starting list, grouped by the behavior each one targets:
- Rare parent-child process chains, for example Office applications spawning a command shell, which is common in initial access.
- Anomalous or encoded PowerShell, long base64-encoded commands, or PowerShell launched from unusual parents.
- New service creation, services installed outside a normal change window, a common persistence move.
- Unusual outbound beaconing, regular, low-volume connections to one external host, which often signals command-and-control.
- Impossible-travel logins, the same account authenticating from two distant locations inside a window too short to travel.
- Spikes in failed authentication, bursts of failures against one account or across many, which can indicate password spraying or credential stuffing.
You write these in your SIEM's language, KQL in Microsoft Sentinel, SPL in Splunk, and each one usually takes a few iterations to tune down the false positives before it's worth running regularly. That tuning is where a lot of hunter time goes.
