Inside Microsoft Threat Intelligence: The Modern Threat Hunter

A man in a grey shirt is shown with a text overlay displaying Thomas Ball Senior Security Researcher Microsoft Defender Experts.

Hunting for Emerging Threats Before They Strike

Threat hunting has always been part science, part instinct. In the latest episode of Inside Microsoft Threat Intelligence, we follow Senior Security Researcher Thomas Ball on our Defender Experts for XDR (DEX) team as he traces a phishing campaign that hijacked Quick Assist—a legitimate Windows tool—to compromise organizations in unexpected ways. His investigation shows how modern defenders work ahead of detections, pulling threads until the full picture emerges.

But today’s threat landscape moves at machine speed. Criminal groups operate like businesses and are rapidly iterating their tooling and techniques. Nation-states deploy precision campaigns that blur the line between espionage and disruption. And, adversaries are experimenting with AI themselves, crafting lures, evading detection, and scaling operations.

In our first episode of Inside Microsoft Threat Intelligence, we showed how Microsoft Threat Intelligence and the Digital Crimes Unit (DCU) disrupted Storm-1152’s massive fake account operation, showing how we turn intelligence into global action.

In episode two, we moved from disruption to response, revealing how calm leadership shapes the outcome of “worst day” security incidents.

Now to episode three, we turn to the hunters, those working behind the scenes to uncover emerging threats before attackers have a chance to strike.

To stay ahead of an AI accelerated threat landscape, Microsoft’s modern threat hunters are changing their approaches too. They’re combining human intuition with AI-powered insight to proactively uncover the unknown.

Hunting What Others Can’t See

For Microsoft’s threat hunters, the job isn’t to wait for an alert to fire, it’s to find the threats no one else has noticed yet. These researchers work on behalf of Microsoft Defender Experts (DEX) customers, proactively scouring telemetry for malicious activity that hasn’t been detected or even documented.

Their leads often come from diverse intelligence sources: Threat intelligence investigations, incident response engagements, open-source research, blogs, GitHub repositories, or even a single post buried on social media. From these fragments, they build hunting hypotheses that allow them to probe Microsoft’s massive signal corpus for subtle traces of attacker activity.

It’s investigative work at scale, made possible by unmatched data visibility across the global ecosystem, and often fueled by AI technology.

AI as a Force Multiplier

The sheer volume of intelligence is both a gift and a challenge. Every day brings thousands of potential leads, and not all are worth chasing. This is where AI changes the game.

Hunters use AI to sift through mountains of signals and prioritize what matters most. It can flag anomalies, highlight relationships between disparate data points, and filter out noise allowing analysts to focus their efforts where they’ll have the most impact.

AI also acts as a real-time research assistant. When a hunter encounters an unfamiliar artifact or technique, they can ask the AI for instant context, accelerating the process of turning fragments into coherent narratives. And once the hunt is complete, AI helps summarize technical findings into clear language for broader audiences, saving valuable time without sacrificing precision. For DEX threat hunters, AI simply amplifies their skills.

From Hypothesis to Detection

A typical hunt follows a deliberate, methodical arc:

Hypothesis generation: An intelligence lead or AI-assisted insight sparks a question worth investigating.
Exploration: The hunter queries Microsoft’s vast telemetry to look for activity patterns, often starting with faint shadows of attacker behavior.
Investigation: As signals coalesce, the hunter follows threads across systems and identities to map the adversary’s actions.
Validation: Once the activity is isolated and repeatable, the team works with Microsoft’s detection engineers to turn hunting queries into robust, low-noise detections.
Protection: These detections roll into Microsoft Defender, notifying customers or stopping attacks in progress.

By the time an attacker realizes they’ve been exposed, the detection is already live at global scale.

Turning Footprints into Intelligence

Attackers try to cover their tracks, but Microsoft hunters see the footprints they leave behind. Whether it’s deleted logs, masqueraded binaries, or subtle behavioral shifts, these traces stand out when you have the telemetry depth Microsoft does.

DEX threat hunters work from a unified system to analyze signals at planetary scale. That combination—unparalleled data, seasoned expertise, and home-grown tooling—means hunters can spot behaviors others simply can’t.

Resilience at Machine Speed

The impact of this work isn’t always visible. Customers rarely see the hunts happening behind the scenes, but they feel the results: faster detections, reduced exposure, and protection from emerging threats before they take root.

In an era where adversaries are experimenting with AI, defenders must move just as quickly. Microsoft’s modern threat hunters embody this shift. By pairing investigative instinct with AI-driven acceleration, they’re pushing threat intelligence from reactive response to proactive resilience.

What’s Next

Threat hunting is just one part of Microsoft’s end-to-end threat intelligence loop—from signal to insight, from hunting to disruption. In the next episode of Inside Microsoft Threat Intelligence, we’ll explore how these insights ripple outward—fueling global operations that protect entire ecosystems, not just individual organizations. For now, you can look back at our previous episodes that cover our intelligence process and disruption actions or a look behind Microsoft Incident Response.

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