How to Start Threat Hunting: A Beginner’s Guide in 2024

Threat hunting is a proactive approach to cybersecurity that involves actively searching for potential threats or indicators of compromise within an organization’s network and systems.

Unlike traditional security measures that rely on detecting known threats, threat hunting aims to uncover advanced persistent threats (APTs) and other sophisticated attacks that may have evaded existing defenses.

If you’re new to threat hunting, this beginner’s guide will provide you with a solid foundation for success.

Understanding the Threat Hunting Process

The threat-hunting process typically involves the following steps:

1. Define the Scope: Determine the areas or systems you want to focus your hunting efforts on, such as critical infrastructure, high-value assets, or areas with known vulnerabilities.
2. Gather Intelligence: Collect and analyze relevant threat intelligence from various sources, including security blogs, forums, and industry reports. This information can help you understand the latest attack techniques and indicators of compromise (IoCs).
3. Create Hypotheses: Based on the gathered intelligence, develop hypotheses about potential threats or attack vectors that could be targeting your organization.
4. Hunt for Indicators: Use various tools and techniques to search for indicators of compromise (IoCs) or anomalies that may signify a potential threat. This can involve analyzing log files, network traffic, endpoint data, and other sources of security data.
5. Investigate and Respond: If you discover any suspicious activity or indicators, conduct further investigation to determine the nature and scope of the threat. If a threat is confirmed, take appropriate remediation steps and update your security controls to prevent similar incidents in the future.
6. Document and Share Findings: Document your findings, including the techniques used, indicators identified, and any lessons learned. Share this information with relevant stakeholders and the broader cybersecurity community to improve collective defense.

Essential Tools and Techniques

To effectively conduct threat hunting, you’ll need various tools and techniques at your disposal. Here are some essential ones to consider:

Security Information and Event Management (SIEM) Tools

SIEM tools collect and analyze security logs from various sources, making them invaluable for threat hunting. Popular SIEM tools include Splunk, QRadar, and LogRhythm.

Endpoint Detection and Response (EDR) Tools

EDR tools monitor and collect data from endpoints (e.g., workstations, servers) to detect and respond to threats. Examples include Carbon Black, Crowdstrike, and SentinelOne.

Network Traffic Analysis Tools

Tools like Wireshark, Zeek (formerly Bro), and Moloch can help you analyze network traffic for suspicious patterns or anomalies.

Threat Intelligence Platforms

Platforms like AlienVault OTX, VirusTotal, and Hybrid Analysis provide access to threat intelligence feeds and allow you to analyze potential threats.

Scripting and Automation

Scripting languages like Python, PowerShell, and Bash can automate various tasks, such as data collection, analysis, and reporting, making the threat hunting process more efficient.

Threat Hunting Tools

To effectively conduct threat hunting, organizations can leverage a variety of tools and technologies, including:

1. Security Information and Event Management (SIEM) Tools: SIEM tools, such as Splunk, ELK Stack, and IBM QRadar, provide centralized logging and analysis capabilities to help identify and investigate security incidents.
2. Endpoint Detection and Response (EDR) Solutions: EDR tools, such as CrowdStrike Falcon, Tanium, and SentinelOne, offer advanced endpoint monitoring and threat detection capabilities to aid in the threat-hunting process.
3. Network Traffic Analysis Tools: Tools like Wireshark, Zeek (formerly Bro), and Suricata can be used to analyze network traffic patterns and identify potential network-based threats.
4. Threat Intelligence Platforms: Platforms like Recorded Future, ThreatConnect, and Anomali provide access to curated threat intelligence data, which can be used to inform the threat-hunting process.
5. Threat Hunting Frameworks: Frameworks like MITRE ATT&CK and Lockheed Martin Cyber Kill Chain can provide a structured approach to threat hunting and help organizations align their efforts with known threat actor tactics, techniques, and procedures (TTPs).
6. Incident Response Tools: Examples: Autopsy, Volatility, Redline – These tools assist security teams in investigating and responding to security incidents, enabling them to collect, analyze, and preserve digital evidence.

Threat Hunting Techniques

1. Indicators of Compromise (IoCs) Analysis: Identifying and analyzing known indicators of compromise, such as file hashes, IP addresses, and domain names, to detect and investigate potential threats.
2. Behavioral Analysis: Monitoring and analyzing user and system behaviors to identify anomalies that may indicate the presence of a threat actor or malicious activity.
3. Threat Hunting Frameworks: Utilizing structured frameworks, such as the MITRE ATT&CK framework, to guide the threat hunting process and align it with known adversary tactics, techniques, and procedures (TTPs).
4. Threat Hunting Methodologies: Employing methodologies like the Diamond Model of Intrusion Analysis or the Cyber Kill Chain to systematically investigate and respond to potential threats.
5. Threat Hunting Playbooks: Developing and implementing customized threat hunting playbooks that outline the specific steps, tools, and techniques to be used in the threat hunting process.
6. Threat Hunting Automation: Leveraging automation tools and scripts to streamline the threat hunting process, enabling security teams to scale their efforts and respond more efficiently to potential threats.

Building a Threat Hunting Team

While a single individual can perform threat hunting, it’s often more effective to have a dedicated team with diverse skills and expertise. A typical threat-hunting team may include:

• Security analysts
• Incident responders
• Malware analysts
• Reverse engineers
• Data scientists
• Subject matter experts (e.g., network, endpoint, cloud)

Collaboration and knowledge sharing within the team are crucial for effective threat hunting.

Threat Hunting Examples

Here are a few examples of threat hunting scenarios:

1. Detecting Lateral Movement: Analyze network traffic and endpoint data to identify patterns of lateral movement, which could indicate the presence of an advanced persistent threat (APT) actor attempting to move deeper into the network.
2. Identifying Unusual User Behavior: Monitor user activity and access patterns to detect any anomalies, such as unusual login times, access to sensitive data, or the use of unfamiliar devices, which could be signs of a compromised user account.
3. Detecting Suspicious File Modifications: Continuously monitor file integrity and changes to identify any unauthorized modifications, which could be indicative of malware or other malicious activities.

Threat Hunting in a New Environment with Splunk

Quickly observing your surroundings, orienting yourself based on those observations, and acting upon them is essential in cybersecurity and life. This tutorial explores the process of threat hunting in a new environment using Splunk.

Starting the Hunt Process

When starting a hunt, it’s essential to have a clear objective in mind. Two approaches are suggested:

1. Developing a Hypothesis: Formulate a hypothesis to steer your efforts, such as “PowerShell is running on my Windows systems.”
2. Using the PEAK Threat Hunting Framework: Establish guardrails around your hunt using this framework.

Focusing Your Hunt

To be effective, you need to narrow the extensive scope of data and time to a more specific range or subset. Here’s how to focus your hunt:

Time

Use the Time Picker in Splunk to set the time range for your search. This is an incredibly important step during any hunt.

Data Sources

Determine the relevant data sources based on your hypothesis or question. For example, if hunting for PowerShell activity, focus on host-based data sources like Microsoft Event Logs and Sysmon. If hunting for data exfiltration, start with network data sources.

Context

In addition to log events, consider contextual data such as asset and identity information, network topology, and threat intelligence to understand the environment better.

Searching in Splunk

When searching in Splunk, start with broad, unstructured searches and then refine your search to tighten your net. Use Splunk’s transforming commands, such as stats and eval, to analyze and manipulate the data.

Using OSINT and Other Resources

Open-source intelligence (OSINT) can be a valuable resource during your hunt. Some recommended OSINT sites include:

• Google: For quickly searching for information like Windows Event codes
• VirusTotal: For researching malware
• RiskIQ: For researching passive DNS
• Censys.IO: For correlating SSL certificates to adversary infrastructure

Threat hunting in a new environment requires a methodical approach. By following the steps outlined in this tutorial, you can effectively start your hunt, focus your efforts, leverage Splunk’s powerful search capabilities, and enhance your investigation by using OSINT.

Continuous Learning and Improvement

Threat hunting is an ongoing process that requires continuous learning and improvement. As new threats and attack techniques emerge, it’s essential to stay up-to-date with the latest developments in the cybersecurity landscape.

To enhance your threat-hunting skills and knowledge, attend security conferences, participate in online forums, and engage with the broader cybersecurity community.

Starting threat hunting can be challenging, but it’s a crucial aspect of modern cybersecurity.

By following this beginner’s guide, you’ll be well on your way to developing the skills and knowledge necessary to identify and mitigate potential threats to your organization proactively.

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