What Is Threat Hunting in Cybersecurity?

If you are new to the wider topic, start with our managed cybersecurity pillar, which sets out how detection, response and hunting fit together for a UK business with 10–500 staff.

What does a threat hunter actually do?

A threat hunter assumes a breach has already happened and goes looking for it. They form a hypothesis — for example, "a compromised account is moving sideways through finance" — then test it against live telemetry. Where automated tools wait for a known pattern, the hunter searches for the unknown.

This matters because the most damaging attacks are designed to look normal. Stolen credentials, legitimate admin tools used maliciously, and slow data theft rarely fire a signature-based alert. Hunting closes that gap by adding human judgement on top of the machine layer. In practice it sits alongside endpoint detection and response rather than replacing it.

• Hypothesis-led: start from attacker behaviour, not from an alert queue.
• Data-driven: correlate endpoint, identity, network and log evidence.
• Outcome-focused: confirm or disprove compromise, then feed findings back into detection rules.

How does threat hunting differ from automated threat detection?

Automated detection uses predefined rules and signatures to flag known threats the moment they match. Threat hunting is analyst-driven: security professionals form hypotheses about attacker behaviour and actively search for indicators of compromise the automated layer has missed. The two are complementary, not interchangeable.

With 43% of UK businesses experiencing a cyber breach or attack in the past year (Cyber Security Breaches Survey 2025, DSIT), the volume alone guarantees that some intrusions slip past rule-based tools. Hunting exists to catch what detection cannot.

The strongest setups run both: automated detection handles scale and speed, while hunting reduces dwell time — the period an attacker stays undetected. This is the model behind managed detection and response (MDR).

Why does threat hunting matter for UK businesses?

It matters because the cost and frequency of undetected intrusions are rising. UK incident data shows attacks are both more common and more disruptive, and the breaches that hurt most are precisely the ones that evade automated alerts. Proactive hunting shortens the window in which an attacker can do damage.

The national picture is stark. The NCSC handled 429 total incidents in 2025, with 204 classified as nationally significant — the highest-ever number (National Cyber Security Centre). At business level, 21% of organisations that experienced a breach reported a negative outcome such as loss of money or data, and 7% reported temporary loss of access to files or networks — up from 4% in 2024 (DSIT 2025).

• Breaches cause real losses: the average cost of the most disruptive breach is £3,550 (DSIT 2025).
• Ransomware is widespread: an estimated 19,000 UK businesses were hit by ransomware in 2025 (Sophos).
• Dwell time is the enemy: the longer an intruder stays hidden, the higher the eventual cost — hunting drives that time down.

For a sense of how this maps to your sector, our cybersecurity pillar breaks down threat patterns by industry.

What data sources do threat hunters use?

Threat hunters work across multiple evidence streams at once. They analyse endpoint telemetry — process executions, file changes and network connections — alongside SIEM log data, identity and authentication records, DNS queries, and external threat intelligence feeds. The skill is in correlating signals that look harmless in isolation.

A hunter looks for anomalies a rule would ignore: a login at 03:00 from an unusual location, an admin tool launched on a finance laptop, lateral movement between systems, or a steady trickle of outbound data. Each on its own is plausible; together they describe an attack. Continuous visibility comes from pairing this with 24/7 security monitoring.

Typical sources include:

• Endpoint and EDR telemetry (process, file, registry, network activity)
• Identity and sign-in logs (Microsoft Entra ID, conditional access events)
• SIEM-aggregated logs from servers, firewalls and applications
• DNS and proxy records for command-and-control patterns
• Curated threat intelligence on current attacker tooling

Do UK SMEs need threat hunting, or is it only for enterprises?

SMEs need it too — but almost never build it in-house. Most access threat hunting as a component of a managed SOC or MDR service, which makes specialist skills affordable without hiring a full security team. Size does not exempt a business; small organisations are routinely targeted precisely because their defences are thinner.

Building an internal hunting capability means recruiting scarce analysts, running tooling around the clock, and retaining that knowledge — rarely viable below a few hundred staff. A managed SOC service delivers the same outcome as a shared, accountable function. When a hunt confirms compromise, the same team runs incident response without a handover.

How is threat hunting delivered in a managed SOC?

In a managed SOC, hunting is a scheduled, repeatable discipline rather than an occasional exercise. Analysts run structured hunts against your telemetry, validate findings, and convert every confirmed technique into a new automated detection — so the machine layer gets smarter each cycle. The business gets enterprise-grade coverage on an SME budget.

AMVIA delivers this with Microsoft Defender for Endpoint telemetry monitored by our in-house 24/7 SOC. One provider owns detection, hunting and response, so there is no finger-pointing between vendors when something is found. That single line of accountability — security-first, Microsoft-certified — is the difference between a tidy report and a contained incident.