The Role of Incident Response in Cybersecurity

Each year, cyber attacks get faster and smarter as attackers become more familiar with traditional incident response (IR) strategies. In years past, these approaches were both error-prone and manually driven, making them more vulnerable to attacks.

In a cybersecurity incident, every second counts. Containment is the most decisive phase of incident response—it stops attackers in their tracks and prevents cascading damage to your operations. Without effective containment, even the best detection, eradication, and recovery efforts can fall apart.

An effective incident response strategy today is one that’s automated, enabling organizations to not only detect, investigate, and respond to threats in real time without human intervention, but to also minimize loss and business disruption.

At the heart of the threat detection, investigation, and response (TDIR) workflow lies a structured incident response lifecycle as defined by industry standards like NIST 800-61. This lifecycle ensures that CISOs and SecOps teams are ready to handle new threats by detecting them early, investigating them thoroughly, and responding timely and decisively.

This guide explores the six phases of the cybersecurity incident response lifecycle, with a focus on why containment is the linchpin of effective incident response. We’ll also dive into the real-world consequences of poor containment, advanced strategies for success, and how automation can make containment faster and more reliable.

The Six Phases of Incident Response

1. Preparation: Build the foundation

This step involves the development of policies, training, and deployment of tools to detect and analyze threats. This can include running regular incident response drills and simulations, assembling an incident response team (IRT), and establishing communication plans for internal and external stakeholders in the case of an attack.

2. Detection and Analysis: Identify and verify the incident

This phase involves identifying suspicious activity, confirming an incident, and assessing impact. Using threat intelligence frameworks like MITRE ATT&CK can help classify the type of attack and its potential impact.

3. Containment: Limit the damage

Containment is the critical inflection point in an incident response program. Think of it as the fire department of your entire system—boots on the ground working quickly to extinguish an attack and preventing it from spreading. Without containment, detection and eradication efforts are severely limited, and attackers can exploit the delay to escalate their operations.

The main goal here is to immediately limit an attack’s impact, then block attackers from gaining further access to your system.

4. Eradication: Eliminate the threat

This step focuses on the removal of malicious artifacts like malware or backdoors, followed by identifying the root cause of the incident. Examples of activities in this phase might include patching vulnerabilities or revoking compromised credentials.

However, eradication can only succeed if containment has stabilized the environment. Without containment, malicious actors can reintroduce threats faster than they can be removed.

5. Recovery: Restore normal operations

Next, security teams restore affected systems and implement ongoing monitoring for reinfections or lingering threats.

6. Post-Incident Activity: Learn and improve

And lastly, security teams should analyze lessons learned post-mortem and collaborate on strategies to improve response processes moving forward.

TIP: Applying the knowledge gained post-mortem to update your incident response plans, playbooks, and security controls can greatly reduce the likelihood and severity of similar incidents in the future.

Each phase plays a critical role in the IR process, but containment is especially crucial in maintaining long-term security.

Why Containment Is Crucial in Modern Cybersecurity

Containment disrupts attacker kill chains by blocking lateral movement, preventing privilege escalation, and limiting the scope of damage. It is the phase that most directly determines whether an attack becomes a minor incident or a full-blown crisis.

Without effective containment, organizations can face extended dwell times, operational disruptions, and expensive recovery costs that, on average, cost businesses $4.88 million in 2024. As attackers get more advanced—embracing ransomware-as-a-service, supply-chain attacks, and zero-day exploits—emphasis on containment is no longer optional; it’s essential to a secure ecosystem.

Containment actions are divided into two categories, the short and long-term, each with distinct goals and purposes:

Short-Term Containment

These are the urgent response actions taken to stop the spread of an attack as soon as it’s detected to prevent escalation. Short-term actions could be endpoint isolation, account lockdowns, blocking malicious traffic, or temporary network segmentation. The careful preservation of evidence in the short-term is also a high priority so you don’t lose or mistakenly destroy forensic data that will support long-term containment.

Long-Term Containment

The goal for long-term containment is to ensure attackers can’t regain access to your system and reestablish a stable environment. Actions like network segmentation reconfiguration, patching vulnerabilities, and credential revocation and replacement can help pinpoint the root cause of an attack. Where short-term actions take seconds or minutes to run, long-term actions are more comprehensive and can take hours up to several days before they’re fully implemented.

Top 5 Incident Response Challenges

Modern organizations face a deluge of new obstacles that makes handling threats more complex. Here’s a breakdown of the top five IR challenges businesses face today:

1. Complexity of Modern IT Environments Hybrid and multi-cloud architectures, shadow IT, and third-party integrations create sprawling attack surfaces. Without a solution that can threats at the source, these complexities make it harder to implement consistent containment strategies across all environments.

2. Alert Fatigue and Tool Overload Security teams are overwhelmed by uncorrelated alerts and redundant tools, leading to inefficiencies and longer response times.

3. Evolving Tactics, Techniques, and Procedures (TTPs) Common perpetrators like APT groups and ransomware operators continuously adapt their methods, rendering traditional IR playbooks less effective.

4. Business Impact of Inefficient Containment Delayed containment + operational downtime + regulatory penalties + reputational damage = $$$ recovery cost.

5. Communication and Coordination Gaps Misalignment between technical teams and executive stakeholders can slow decision-making during high-stakes incidents, compounding the overall impact.

Advanced Containment Strategies

The use of advanced automation tools and ML- and AI-powered solutions are leading the charge for the containment of emerging threats. These new technologies are already effectively driving short- and long-term containment. Here’s an overview of the methods and strategies for modern advanced containment:

Strategic Containment Goals

  • Limit Attacker Success: AI models can predict an attacker’s next move by analyzing historical attack patterns, enabling security teams to proactively block access to critical systems or sensitive data.
  • Preserving Evidence: ML algorithms can identify and flag malicious artifacts, ensuring that forensic evidence is collected securely and without contamination.
  • Reducing MTTC: AI-powered analytics accelerate decision-making by prioritizing containment actions in real-time based on threat severity and business impact.

By using advanced ML- and AI-powered tools, organizations can automate containment faster and more accurately than traditional methods.

Tactical Containment Methods

  • Segmentation and Micro-Segmentation: Dynamically segment networks to isolate threats at both application and network layers.
  • Endpoint Isolation: Use EDR tools to quarantine compromised systems without disrupting unaffected operations.
  • Access Control Adjustments: Temporarily revoke privileged credentials or enable just-in-time access to limit exposure.

Automated Containment

  • Phishing Attack: Automated workflows can detect malicious emails, block phishing URLs, and reset user credentials within seconds.
  • Malware Attack: Automation can isolate affected systems, scan for additional infections, and remove malware while applying necessary patches—all with minimal human intervention.

Threat Intelligence Integration

Automation integrates real-time threat intelligence into containment strategies, dynamically updating IP blacklists, indicators of compromise (IOCs), and response actions based on current threats.

Tips for Optimizing Incident Response Containment

Organizations must adapt containment strategies to their broader TDIR workflows. Below are a few key tips for optimizing IR containment:
Create Actionable Playbooks: Create scenario-based playbooks for common threats, such as ransomware or phishing, and incorporate automated actions like endpoint isolation and IP blocking for consistent execution.

  • Why It Matters: Playbooks provide a standardized, repeatable framework for responding to specific types of cyber threats, ensuring consistency and reducing decision-making delays during incidents.

Leverage Advanced Detection and Analysis: Deploy tools like behavioral analytics and anomaly detection to identify threats early and accurately.

  • Why It Matters: Early and accurate detection is the foundation of effective containment. Without it, security teams can waste valuable time chasing false positives or miss signs of a real attack.

Implement Dynamic Policies: Adopt adaptive security controls that adjust containment measures in real -time based on risk levels.

  • Why It Matters: Static security policies are often too rigid to address the dynamic nature of modern threats. By adjusting to your unique needs and environment, adaptive policies allow organizations to respond faster to evolving risks.

Prioritize Critical Assets: Focus containment efforts on business-critical systems and high-risk attack surfaces.

  • Why It Matters: Not all systems or data are created equal. Focusing containment efforts on high-value targets minimizes the potential impact of an attack and reduces recovery time.

Conduct Regular Incident Simulations: Test containment strategies through red team exercises, breach-and-attack simulations, and purple teaming to identify gaps.

  • Why It Matters: Regular testing ensures that containment strategies are effective and helps identify gaps in your processes before a real attack occurs.

Foster Cross-Functional Collaboration: Streamline communication between security operations, IT, and DevOps teams to ensure faster and more coordinated responses.

  • Why It Matters: Incident response often requires coordination across multiple teams, including IT, security, legal, and executive leadership. Miscommunication during high-stakes incidents can delay containment efforts and worsen the impact.

Supporting the Business Through Effective Containment

It’s critical to strike the right balance between effective containment and business continuity. For example, automated actions like isolating a compromised endpoint without taking the entire network offline is an outcome you should strive for. Here are a few other goals to keep your business operations in check:

  • Metrics That Matter to Leadership: Mean Time to Contain (MTTC): Time taken to stop an attack from spreading.
  • Incident Escalation Time: Speed of communication to stakeholders.
  • Average Breakout Time: The time it takes for an attacker to achieve lateral movement.
  • Reducing Long-Term Business Risks: Effective containment minimizes breach recovery times, compliance penalties, and reputational harm. It also ensures customer trust and operational resilience.

Aligning Security Operations with Business Objectives: Containment strategies should align with broader organizational goals, such as upholding SLAs, meeting compliance requirements, and maintaining customer satisfaction.

Building Resilience Through Advanced Containment

Containment isn’t just another phase of incident response—it’s the foundation upon which all other phases rely. By stopping attackers in their tracks, containment buys organizations the time and stability needed to recover and adapt. By leveraging AI, machine learning, automation, and orchestration tools, organizations can ensure appropriate actions are run with speed, precision, and consistency.

Orchestrate Incident Response with ReliaQuest GreyMatter

ReliaQuest GreyMatter, an AI-powered security operations platform, contains threats in less than 5 minutes, effectively eliminating mundane Tier 1 and Tier 2 chores. By reducing the low-brain, high-time activities that bog down your team, GreyMatter gives analysts the freedom to focus on higher-value work. Using agentic AI, GreyMatter automates complex workflows; enables faster, smarter decisions; and unifies your tools and processes so your entire ecosystem works together seamlessly.

Thanks to its agnostic architecture, GreyMatter integrates seamlessly with your existing environment, and its intuitive design means analysts of any experience level can operate like seasoned pros. Whether it’s automating repetitive tasks or scaling responses across your ecosystem, GreyMatter helps you take control of your operations–on your terms.