Proactive threat hunting with Talos IR

At Cisco Talos, we understand that effective cybersecurity isn’t just about responding to incidents — it’s about preventing them from happening in the first place. One of the most powerful ways we do this is through proactive threat hunting. Our Talos Incident Response (Talos IR) team works closely with organizations to not only address existing threats but to anticipate and mitigate potential future risks. A key component of our threat-hunting approach is the Splunk SURGe team’s PEAK Threat Hunting Framework, which enables us to conduct comprehensive and proactive hunts with precision.

What is the PEAK Threat Hunting Framework?

The PEAK Framework (Prepare, Execute, and Act with Knowledge) offers a structured methodology for conducting effective and focused threat hunts. It ensures that every hunt is aligned with an organization’s specific needs and threat landscape. At the core of the PEAK framework are baseline hunts, which lay the foundation for proactive threat detection, alongside advanced techniques such as hypothesis-driven hunts and model-assisted threat hunts (M-ATH), which further enhance threat detection and mitigation.

Baseline hunts: the foundation of proactive threat hunting

Baseline hunts involve establishing a clear understanding of an organization’s normal operating environment in terms of user activity, network traffic and system processes. By documenting and analyzing this baseline, Talos IR can identify anomalous behavior that may signal malicious activity.

While these hunts can be a reactive measure, it’s important to use them proactively to detect threats trying to blend in with regular operations, such as insider threats, advanced persistent threats (APTs) and even novel attack techniques that might otherwise go undetected.

The key steps in baseline hunts are:

Defining Normal Activity: Understanding what “normal” looks like in your environment, using data from system logs, user behavior, and network traffic.
Anomaly Detection: Proactively hunting for deviations from the baseline that could indicate potential threats.
Refining the Baseline: Continuously improving and updating the baseline to account for emerging threats and changes in your infrastructure.

Hypothesis-driven hunts: Testing assumptions about threats

In addition to baseline hunts, Talos IR also uses hypothesis-driven hunts to proactively test assumptions about potential threats. These hunts are guided by specific hypotheses or educated guesses about what attackers might be doing in a given environment. Rather than relying on a static, one-size-fits-all approach without adjustments, hypothesis-driven hunts are dynamic, adapting to the specific questions and emerging threats that arise.

For example, a hypothesis-driven hunt might begin with the assumption that a particular group of users is being targeted by a phishing campaign. The hunt would focus on testing this assumption by looking for evidence of malicious emails, unusual login patterns or attempts to collect or exfiltrate data.

The key steps in hypothesis-driven hunts are:

Forming Hypotheses: Based on threat intelligence and past incidents, teams generate specific hypotheses about possible attack vectors or adversary behaviors.
Testing Hypotheses: Using data sources such as endpoint telemetry, authentication logs or network traffic, the hypothesis is tested to see if evidence supports the theory.
Analyzing Results: If the hypothesis is validated, further investigation is done to understand the full scope of the potential threat.

Model-assisted threat hunts: Leveraging machine learning to find hidden threats

Another powerful tool in Talos IR’s proactive hunting approach is model-assisted threat hunts (M-ATHs). These hunts leverage machine learning and advanced statistical models to sift through vast amounts of data and identify patterns that may indicate hidden threats. M-ATHs allow our team to detect threats that would be difficult to find using traditional methods.

Machine learning models are trained to detect suspicious behavior across different domains — such as user activity, network traffic or system logs — by looking for deviations from typical patterns. Over time, as these models learn from new data and threat intelligence, they improve in their ability to detect emerging threats.

The key steps in M-ATHs are:

Data Collection: Gathering large datasets from multiple sources, including network traffic, endpoint data, authentication logs, and more.
Model Training: Using machine learning algorithms to identify patterns in normal and malicious behavior.
Anomaly Detection: The trained model helps identify new, previously undetected anomalies or potential threats by looking for deviations from established patterns.
Refinement: The model is refined as new data is collected and analyzed, improving its ability to detect subtle threats.

Empowering threat hunts with Talos Threat Intelligence

A crucial element that enriches and empowers every Talos IR threat hunt is Talos Threat Intelligence. By integrating up-to-date, high-fidelity threat intelligence into our hunts, we enhance the accuracy, relevance, and speed of our investigations. Talos Threat Intelligence provides a continuous stream of data on emerging threats, attack trends and adversary tactics, which helps us refine hypotheses, adjust baselines and improve our machine learning models.

This intelligence is not just a complement to our hunting process; it is embedded in every stage. It helps guide our hypothesis-driven hunts, sharpens our baseline detections and feeds into the models we use for anomaly detection. With Talos Threat Intelligence, we ensure that every hunt is aligned with the latest threat landscape, empowering your team with the knowledge needed to stay one step ahead of attackers.

Proactive engagements for IR Retainer customers

For Talos IR Retainer customers, baseline hunts, hypothesis-driven hunts, and model-assisted threat hunts provide a valuable layer of ongoing, proactive support. These hunts help organizations detect and mitigate threats before they escalate into full-blown incidents. Our expert hunters work directly with your teams, ensuring that you stay ahead of evolving threats.

Some key benefits of these proactive engagements include:

Early Detection: Identifying abnormal activities that could signal a breach or malicious action, reducing the risk of an attack spreading.
Continuous Improvement: As we refine the baseline and hunting models, your security posture improves over time, allowing for faster and more accurate threat detection.
Actionable Insights: Proactive hunts deliver actionable intelligence that helps your teams strengthen their defenses, based on the latest threat trends and attack methods.

Why it matters

The cybersecurity landscape is constantly evolving, and traditional defensive methods alone are no longer sufficient. Threat actors are adept at blending malicious activity with normal operations, making it difficult to spot attacks using conventional means. By conducting baseline hunts, hypothesis-driven hunts and model-assisted threat hunts, Talos IR gives your organization the tools it needs to stay ahead of adversaries.

As new evidence is uncovered during a hunt, our team adapts and refines the investigation in real time — evolving the hypothesis, adjusting the scope or pivoting to new areas of focus based on what the data reveals.

If an active threat, adversary or malicious activity is detected during a hunt, Talos IR can dynamically pivot the engagement and escalate the situation to our 24/7 on-call Incident Response team. This ensures rapid response for containment, mitigation and eradication, effectively minimizing the potential impact of the threat.

Our Talos IR team collaborates seamlessly with the hunting team to deliver real-time support in identifying, isolating and neutralizing active threats. This integrated approach ensures your systems remain secure and prevents the threat from escalating further.

At Talos, our goal is to empower your team with the knowledge and tools to detect threats proactively, before they turn into incidents. Through our IR Retainer services, we provide continuous support to help you improve your security posture and stay one step ahead of emerging threats, all while leveraging the full power of Talos Threat Intelligence.