Threat Hunting Definition

The median duration between an actual security breach and its detection, otherwise termed dwell time, is usually several weeks, if not months. This implies a potential adversarial presence within a network for a span approaching three weeks, a duration that can be significantly impactful.

This alarming fact underscores the growing inefficacy of traditional, defense-oriented cybersecurity tactics. In response, a paradigm shift towards a proactive, offensive strategy has emerged — the initiation of threat hunting.

Threat hunting is an active, human-led, and often hypothesis-driven practice that systematically combs through network data to identify stealthy, advanced threats that evade existing security solutions. This strategic evolution from a conventionally reactive posture allows defenders to uncover insidious threats that automated detection systems or external entities such as law enforcement might not discern.

The principal objective of threat hunting is to substantially reduce dwell time by recognizing malicious entities at the earliest stage of the cyber kill chain. This proactive stance has the potential to prevent threat actors from entrenching themselves deeply within the infrastructure and to swiftly neutralize them.

Threat Hunting Process

The threat hunting process begins with the identification of assets — systems or data — that may represent high-value targets for threat actors. Subsequently, analysts examine the TTPs (Tactics, Techniques, and Procedures) adversaries are likely to employ, informed by up-to-date threat intelligence.

Threat hunters proactively attempt to detect, isolate, and validate any artifacts related to the identified TTPs or any anomalous behavior that deviates from defined baselines of normal network activity.

Throughout this process, Threat Intelligence plays a pivotal role. It supports the formulation of hunting hypotheses, the development of countermeasures, and the implementation of protective strategies aimed at preventing system compromise.

Key Characteristics of Threat Hunting

• An offensive, proactive strategy that prioritizes threat anticipation over reaction, grounded in hypotheses, attacker TTPs, and current intelligence.
• A reactive investigative mode that explores the network in response to confirmed incidents, leveraging evidence and threat data.
• A thorough understanding of the threat landscape, including common cyber threats, adversary behaviors, and the cyber kill chain model.
• The application of cognitive empathy to understand the attacker’s objectives, methods, and mindset.
• In-depth familiarity with the organization’s IT environment, including network topology, asset inventory, and patterns of normal behavior.
• Use of high-fidelity telemetry, tactical analytics, and advanced threat hunting platforms and tools.

Incident Handling & Threat Hunting

How does threat hunting intersect with the various phases of incident handling? This section explores how these two disciplines complement one another throughout the incident management lifecycle.

Preparation Phase

In the Preparation phase of incident handling, a threat hunting team must establish clear and robust rules of engagement. Operational protocols should define when and how hunters intervene, detailing courses of action for specific scenarios. Some organizations choose to integrate threat hunting into existing incident response procedures, eliminating the need for separate policies and frameworks.

Detection & Analysis Phase

During the Detection & Analysis phase, the expertise of a threat hunter becomes invaluable. Hunters support investigations by validating whether observed Indicators of Compromise (IoCs) truly represent an incident. Their adversarial mindset and knowledge of TTPs enable them to identify additional artifacts or threats that automated systems may have overlooked.

Containment, Eradication & Recovery Phase

In the Containment, Eradication, and Recovery phase, the hunter’s role can vary significantly depending on organizational policy. In some cases, hunters are directly involved in executing containment strategies, assisting in eradication efforts, and validating successful recovery. However, this involvement is not standardized and depends on whether the organization explicitly defines these responsibilities in their procedural documentation and security policies.

Post-Incident Activity Phase

During Post-Incident Activities, threat hunters can contribute their cross-disciplinary IT and security expertise to enhance the organization’s future readiness. Their insights can lead to tactical and strategic recommendations that strengthen the overall security posture and reduce the likelihood of recurrence.

Strategic Integration Considerations

Ultimately, whether threat hunting and incident handling should operate as integrated functions or remain distinct is a strategic decision. This choice depends on the organization’s specific threat landscape, risk profile, and operational maturity. Regardless of the structure, their synergy enhances the ability to proactively detect, respond to, and learn from cyber threats.

Team's Structure

Building an effective threat hunting team is a strategic endeavor that demands a multidisciplinary set of skills, perspectives, and operational knowledge. Each member must contribute unique competencies that, collectively, enable a comprehensive approach to threat detection, mitigation, and response.

An optimal threat hunting team typically comprises a blend of technical specialists, analysts, and operations personnel. The roles outlined below illustrate the core components of such a team.

Threat Hunter

The threat hunter is the foundational role within the team. These professionals possess deep familiarity with the threat landscape, adversary Tactics, Techniques, and Procedures (TTPs), and advanced threat detection methodologies. They proactively search for Indicators of Compromise (IoCs), leveraging a variety of threat hunting platforms, scripting tools, and behavioral analytics to uncover hidden or advanced threats that evade traditional detection mechanisms.

Threat Intelligence Analyst

The threat intelligence analyst is responsible for collecting, correlating, and contextualizing data from multiple intelligence sources — including open-source intelligence (OSINT), dark web forums, commercial threat feeds, and industry-specific reports. Their objective is to maintain situational awareness of emerging threats, adversary campaigns, and evolving tactics, thereby empowering threat hunters with actionable intelligence.

Incident Responder

The incident responder takes action when potential threats are identified. Their duties encompass the full incident lifecycle: initial investigation, containment, eradication, and recovery. They collaborate closely with hunters to validate threats and ensure swift remediation, minimizing operational disruption and preventing recurrence.

Forensics Expert

The forensics expert specializes in digital forensics and incident response (DFIR). These professionals conduct deep-dive technical analysis of compromised systems, perform memory and disk forensics, reverse engineer malware, and produce detailed post-incident reports. Their work is essential for attributing attacks and refining future detection strategies.

Data Analyst / Data Scientist

Data analysts and scientists focus on extracting meaningful insights from large and complex datasets. They apply statistical analysis, machine learning models, and data mining techniques to detect anomalies, behavioral patterns, and potential indicators of malicious activity. Their contributions support both strategic hunting operations and the continuous improvement of detection logic.

Security Engineer / Architect

Security engineers and architects design, build, and maintain the underlying security infrastructure. They ensure that detection tools, log aggregation systems, and hunting platforms are optimally deployed and aligned with threat hunting requirements. They also implement preventive controls and security automation to reinforce the organization’s defense-in-depth strategy.

Network Security Analyst

The network security analyst monitors and interprets network traffic, protocol usage, and communication patterns. Their expertise in baseline network behavior allows them to detect traffic anomalies, lateral movement, and exfiltration attempts. They play a critical role in validating network-based IoCs and mapping attack paths across the infrastructure.

SOC Manager

The Security Operations Center (SOC) manager oversees the daily operations of the threat hunting team and ensures cross-functional coordination. This role bridges strategic decision-making and operational execution, facilitating efficient workflows, resource allocation, and communication with executive leadership and external stakeholders.

Introduction

Threat hunting is a structured, iterative process that blends proactive research, data analysis, and continuous improvement. Below is a detailed breakdown of the key phases that constitute an effective threat hunting cycle.

Setting the Stage

This initial phase focuses on preparation and planning. It involves identifying clear objectives based on a deep understanding of the threat landscape, business priorities, and current threat intelligence. The environment must be equipped for data visibility through extensive logging and properly configured tools such as SIEM, EDR, and IDS. Teams should also remain informed on emerging threats and adversary profiles.

Example: The team conducts research on current threat reports, identifies industry-specific vulnerabilities, and maps known TTPs. Critical assets are cataloged, logging is enabled on endpoints and servers, and tools are configured for full telemetry. Intelligence feeds and community alerts are monitored to remain current on relevant threats.

Formulating Hypotheses

A testable hypothesis is proposed to guide the hunt. These hypotheses can be informed by threat intelligence, anomaly alerts, recent incidents, or even intuition. A clear and specific hypothesis helps focus the investigation and determines where and how to look for evidence.

Example: A hypothesis might state that an APT group is exploiting a known vulnerability in a web server to establish a command-and-control (C2) channel. This is based on recent alerts and observed network behavior indicative of lateral movement or remote access attempts.

Designing the Hunt

With a hypothesis in place, the team outlines a hunting plan. This includes selecting relevant data sources (logs, telemetry, DNS data), defining indicators of compromise (IoCs), and crafting search queries, filters, or custom scripts. Specialized threat hunting platforms or automation tools may assist in operationalizing the hunt.

Example: The team targets server logs, DNS records, and endpoint telemetry. They write YARA rules or custom queries to detect malicious file hashes or suspicious traffic. OSINT and CTI sources help define additional IoCs aligned with the hypothesis.

Data Gathering and Examination

This is the execution phase, where data is actively collected and analyzed to validate or refute the hypothesis. It involves reviewing logs, analyzing network traffic, and inspecting endpoints using analytical techniques such as behavioral analysis, anomaly detection, or signature matching. This phase is iterative and may lead to hypothesis refinement.

Example: The team analyzes access logs for irregular patterns, inspects packet captures for suspicious domains, and examines endpoint logs for abnormal user activity. They use tools like packet analyzers, log parsers, or sandbox environments to investigate the presence of malware or exploitation artifacts.

Evaluating Findings and Testing Hypotheses

After analysis, findings are interpreted to confirm or disprove the hypothesis. The team identifies affected systems, determines the threat’s behavior, and assesses its potential impact. These results inform decisions on mitigation, escalation, or further investigation.

Example: Evidence of repeated login attempts from a malicious IP validates a brute-force hypothesis. DNS logs confirm connections to known malicious infrastructure, supporting the theory of C2 activity. The team assesses lateral movement and determines the scope of exposure.

Mitigating Threats

Once a threat is confirmed, remediation actions are implemented. This includes isolating systems, removing malware, patching vulnerabilities, and updating configurations. The objective is to eradicate the threat, contain the spread, and restore secure operations.

Example: A system communicating with a C2 server is removed from the network. Malware is eradicated using endpoint protection tools. Vulnerabilities are patched and firewall rules are adjusted to block malicious IPs or ports. Forensic analysis reveals the timeline and method of compromise.

After the Hunt

After completing the hunt, documentation is critical. Findings, methodologies, and outcomes are recorded. Detection rules and response procedures are refined, and threat intelligence platforms are updated with new IoCs. Lessons learned are shared across teams to strengthen future operations.

Example: IoCs discovered during the hunt are uploaded to internal and external threat intel platforms. SIEM correlation rules are enhanced, and the IR playbook is updated. Security awareness and training content is revised based on attacker techniques encountered.

Continuous Learning and Enhancement

Threat hunting is an ongoing process. Each iteration informs the next by refining hypotheses, techniques, and detection capabilities. Teams should regularly evaluate their processes, stay current with evolving threats, and adopt new tools or frameworks to improve hunting efficiency.

Example: The team holds post-hunt reviews to assess effectiveness, identifies areas for improvement, and explores new approaches like integrating behavioral analytics or machine learning. Participation in security conferences, threat intel communities, and red-blue team exercises helps build skills and awareness of novel threat vectors.

Threat Hunting VS Emotet

The following section illustrates how the structured threat hunting process can be applied to detect and respond to Emotet malware within an organization.

Emotet is a modular trojan that has evolved into a malware delivery platform and botnet. Initially designed to steal credentials, it now spreads other malware (like TrickBot or ransomware) via malicious email campaigns, often using macro-enabled attachments or phishing links. Emotet is known for persistence techniques, evasion mechanisms, and reusing email threads to appear legitimate. Despite being taken down in 2021, it resurfaced and remains an active global threat.

Setting the Stage

The threat hunting team conducts focused research on Emotet’s TTPs by analyzing previous campaigns, malware samples, and threat intelligence reports. They study Emotet’s delivery methods, such as phishing emails with malicious Word documents, and identify commonly targeted systems like email servers and high-privilege endpoints. Logging is enabled across key infrastructure, and SIEM/EDR tools are configured to detect Emotet-specific behaviors.

Formulating Hypotheses

Based on recent intelligence, the team hypothesizes that Emotet is being distributed via compromised email accounts using phishing emails with macro-laden attachments. Alerts from the email gateway detecting similar subject lines and attachment types support this assumption.

Designing the Hunt

The team focuses on email server logs, DNS logs, and endpoint telemetry. Queries are crafted to detect patterns like repeated delivery of macro-enabled documents, PowerShell execution after email receipt, and outbound traffic to known Emotet C2 servers. IOC correlation includes file hashes, malicious domains, and sender behavior.

Data Gathering and Examination

Email access logs reveal suspicious attachments from external accounts. DNS logs show beaconing behavior to Emotet infrastructure. Endpoint data confirms macro execution and command-line activity post-delivery. Network captures and sandbox detonation identify encoded payloads matching Emotet variants.

Evaluating Findings and Testing Hypotheses

The hypothesis is confirmed: multiple endpoints interacted with known C2 domains, and a consistent phishing pattern is observed. Credential theft and lateral movement attempts are detected. The infection timeline is reconstructed, and affected assets are identified.

Mitigating Threats

Infected endpoints are quarantined. Email accounts used in the phishing campaign are disabled. EDR tools are deployed to remove malware, and firewall rules are updated to block Emotet-related infrastructure. Vulnerable software is patched, and lateral movement paths are closed.

After the Hunt

All IoCs are documented and shared with threat intelligence platforms. SIEM detection rules are updated to match observed behaviors. The IR playbook is updated with Emotet-specific response actions, and user awareness training is reinforced to counter phishing vectors.

Continuous Learning and Enhancement

The team adjusts its hunting methodology based on Emotet’s latest evasion techniques. New heuristics and anomaly detection models are developed. Threat feeds are monitored for Emotet campaigns, and the team engages in collaborative information sharing and training exercises.

Adversary

An adversary is an entity that seeks unauthorized access to systems or data for purposes such as financial gain, espionage, or disruption. Adversaries vary in skill and motivation and are typically categorized as cybercriminals, insider threats, hacktivists, or state-sponsored actors.

Advanced Persistent Threat (APT)

APTs are highly organized and resource-rich threat actors, often nation-state affiliated, capable of sustaining long-term operations. Their focus is typically on high-value targets. The term “advanced” refers to strategic planning, not necessarily technological sophistication, while “persistent” emphasizes the long-term dedication to objectives.

Tactics, Techniques, and Procedures (TTPs)

TTPs define an adversary’s behavior:

• Tactics: The adversary’s high-level objectives ("why").
• Techniques: General approaches used to achieve those goals ("how").
• Procedures: Specific implementations or steps taken.

Understanding TTPs helps construct effective Indicators of Compromise (IOCs) and defensive strategies.

Indicator

An indicator combines technical data with context to provide meaningful insights during threat analysis. Raw data alone is insufficient — data plus context equals indicator.

Threat

A threat consists of three components: Intent (the adversary’s objective), Capability (tools/resources), and Opportunity (conditions allowing action). Only when all three align does a threat become active.

Campaign

A campaign is a collection of incidents linked by common TTPs and objectives. Identifying campaigns requires aggregation and analysis across multiple events and data sources.

Indicators of Compromise (IOCs)

IOCs are digital artifacts left behind from cyber intrusions, such as file hashes, domain names, malicious scripts, or IP addresses. Monitoring IOCs improves early detection and enhances incident response.

Pyramid of Pain

The Pyramid of Pain illustrates the difficulty of detecting indicators and the impact on adversaries. Created by David Bianco, it shows that identifying higher-level indicators like TTPs forces adversaries to make costly changes.

Hash Values

Hash values are unique file identifiers generated by algorithms like MD5 or SHA-256. They help detect malware but are easily changed with minimal file modifications, reducing their reliability.

IP Addresses

IP addresses identify network endpoints but are easy to obfuscate using VPNs, proxies, or TOR. Their ease of manipulation makes them less reliable as indicators.

Domain Names

Domains may map to multiple IPs and are often manipulated using Domain Generation Algorithms (DGAs) or dynamic DNS, making them moderately useful but easily replaceable.

Network/Host Artifacts

Network artifacts include DNS queries, NetFlow, or packet data that reflect an attacker’s activity. Host artifacts are traces on local systems such as registry keys, unusual DLLs, or suspicious processes. These are harder to forge without disrupting the attack chain.

Tools

Tools include malware, scripts, or frameworks used by adversaries. Identifying tools helps assess capability and attribution, though sophisticated actors may modify or rotate tools frequently.

TTPs (Tactics, Techniques, and Procedures)

TTPs are the most valuable but hardest-to-change indicators. They describe what the adversary is trying to achieve and how. Detecting TTPs enables long-term, resilient defense strategies.

Diamond Model

The Diamond Model describes cyber intrusions through four interlinked elements:

This model provides analytical depth and supports predictive defense. For example, a cybercriminal (Adversary) uses spear-phishing (Capability) from a botnet (Infrastructure) to infect a financial institution (Victim). By understanding the relationships between these vertices, defenders can break the attack chain and anticipate future activity.

The Diamond Model complements the Cyber Kill Chain by focusing on entities and relationships rather than stages. Both are valuable for designing effective detection and response strategies.

Introduction

Cyber Threat Intelligence (CTI) represents a critical capability that empowers organizations to transition from reactive defense to a proactive, intelligence-driven posture. It provides the Security Operations Center (SOC) with strategic, operational, and tactical insights that support the detection, analysis, and mitigation of emerging threats.

The overarching goal of the CTI function is to anticipate threat actor behavior, reduce uncertainty in decision-making, and enable timely, effective defensive actions. CTI acts as a bridge between threat data and security operations, turning raw information into contextualized intelligence that is both actionable and aligned with organizational priorities.

Core Principles of Effective CTI

For CTI to serve its intended purpose, it must embody four foundational characteristics: Relevance, Timeliness, Actionability, and Accuracy. These principles ensure that intelligence contributes to meaningful defense outcomes rather than becoming noise within the security workflow.

Relevance

With the cybersecurity ecosystem flooded with data—from social media, industry reports, open-source feeds, and vendor intelligence—the true value lies in selecting what matters most to your environment. Intelligence is only relevant when it pertains to your assets, technologies, partners, or known threat landscape. For instance, a vulnerability report for a system not deployed within your network requires a different response priority than one affecting business-critical infrastructure.

Timeliness

Timely intelligence enables preemptive or immediate action. Information delivered after the adversary has changed infrastructure or completed objectives is of diminished value. CTI must strive to deliver real-time or near-real-time insight to ensure that security controls can be adjusted, detection rules updated, and response procedures enacted before damage occurs.

Actionability

Threat intelligence must lead to action. Whether blocking an IP, deploying a detection signature, or launching a threat hunting operation, every piece of intelligence must support operational outcomes. Intelligence that cannot drive a decision or control adjustment becomes what is often referred to as a "self-licking ice cream cone"—a cycle of consumption and analysis without security benefit.

Accuracy

Before dissemination, intelligence must be vetted for fidelity and confidence. Misattributed TTPs, false-positive indicators, or flawed campaign attributions can misdirect efforts and consume valuable resources. CTI should tag intelligence with confidence levels (e.g., low, medium, high) based on source credibility and evidence strength. This allows downstream consumers to act with an appropriate level of caution or urgency.

Strategic Outcomes Enabled by CTI

When relevance, timeliness, actionability, and accuracy converge, CTI enables significant advancements in cyber defense maturity. These include:

• Gaining foresight into ongoing adversary campaigns and emerging tactics targeting your organization or sector.
• Enriching telemetry and alerts through contextual analysis conducted by CTI analysts and security engineers.
• Identifying and mapping adversary TTPs to develop focused detection and mitigation strategies.
• Equipping business and technical leadership with intelligence-driven insights to inform risk management and operational decision-making.

Threat Intelligence vs Threat Hunting

Threat Intelligence and Threat Hunting are two distinct yet interconnected cybersecurity disciplines. While each fulfills a unique function, both play a critical role in enhancing an organization's detection and response capabilities. They are complementary—not interchangeable—and together contribute to a more resilient security posture.

Threat Intelligence (Predictive)

The core function of Threat Intelligence (CTI) is predictive in nature. It seeks to anticipate adversarial behavior by analyzing external data sources, identifying threat actors, and forecasting potential attack vectors. CTI teams attempt to answer critical strategic questions about the adversary:

• Where is the adversary likely to attack?
• When is the attack expected to occur?
• What methods or operational strategies will be employed?
• What are the adversary’s ultimate objectives?

Threat Intelligence outputs can include adversary profiles, Indicators of Compromise (IOCs), Tactics, Techniques, and Procedures (TTPs), and situational analysis reports. These outputs are crucial for informing detection strategies, guiding risk assessments, and supporting decision-making at both technical and executive levels.

Threat Hunting (Reactive and Proactive)

Threat Hunting operates on a different axis—it is both reactive and proactive. It is initiated in response to:

• Specific incidents within the organization
• Emerging threats observed in similar industry sectors
• Alerts or weak signals identified by detection systems

The hunting team actively searches through systems and datasets to identify signs of compromise, lateral movement, or undetected malicious activity. The goal is to validate the presence or absence of adversaries who may have evaded traditional defenses, and to uncover anomalous behavior that aligns with known or suspected threat activity.

Mutual Reinforcement

Threat Intelligence and Threat Hunting are not siloed operations. Instead, they support and enrich each other. CTI provides context, direction, and priority to threat hunting missions. This includes adversary infrastructure, campaign indicators, or high-risk assets to monitor. In return, threat hunting findings—such as newly discovered artifacts, behaviors, or unknown TTPs—feed back into the CTI process, improving the accuracy and relevance of intelligence products.

Together, these two disciplines form a powerful feedback loop that enhances situational awareness, improves detection capabilities, and accelerates incident response.