Cyber Security Incident Response: Definition & Best Practices

Cyber security incidents are increasing in frequency. Cyber security incident response is a strategic approach to identify an incident and minimize its impact before it causes too much damage.

Cybersecurity incidents are increasingly frequent and sophisticated. No matter how much effort you put into defending your organization from a cybersecurity incident, you can never be 100% secure. According to IBM, the average time to identify a breach is 194 days and the average cost of a data breach is $4.88 million in 2024. Therefore, organizations should remain vigilant and prepared.

Cybersecurity incident response is a strategic approach to identify an incident and minimize its impact before it causes too much damage. However, it’s beneficial only if done right. So in this post, let’s define cybersecurity incident response, its life cycle, the challenges of incident response, and the best practices to follow for an effective incident response.

What Is Cybersecurity Incident Response?

A cybersecurity incident response, commonly called incident response in the cybersecurity industry, is a systematic process of detecting, managing, and mitigating cybersecurity incidents. It covers everything from detecting and investigating an incident to recovering from the impact of the incident. The goal of cybersecurity incident response is to

• detect incidents quickly,
• investigate them thoroughly,
• contain and minimize the impact of incidents,
• mitigate the damage, and
• and restore the status quo efficiently and cost-effectively.

To achieve this, organizations should take a well-planned approach. Next, let’s see what an incident response looks like.

Overview of the Incident Response Life Cycle

A cybersecurity incident poses several risks and potential impacts that can be catastrophic for an organization. When dealing with a cybersecurity incident, time is of the essence. Therefore, organizations need to deal with incidents strategically. The incident response life cycle acts as a reference for organizations to plan and prepare for dealing with an incident. It addresses different phases of incident response and highlights the tasks to complete during each phase. While some organizations may have customized their approaches to incident response, cybersecurity incident response has six main phases.

What Are The 6 Steps of NIST (National Institute of Standards and Technology) Incident Response?

The six steps of incident response according to the National Institute of Standards and Technology are as follows:

1. Preparation

Preparation is the first and the most important phase of the incident response life cycle as it sets the foundation for all the subsequent phases.

It starts with understanding the different threats that the organization faces and their impact. Then, you develop an incident response plan (IRP) and the standard operating procedures (SOPs) to handle an incident, and a detailed plan with the roles and responsibilities of every individual and team and the steps to take when an incident occurs, which teams and stakeholders to inform and through what channels, which tools to use, reporting guidelines, and an escalation framework.

Another part of preparation is to ensure that the individuals involved in incident response are trained to handle the different types of incidents and to use the tools and technologies they use. The security team(s) should set up and configure tools for detection, investigation, containment, backup, and recovery. Test all implementations regularly to make sure they work as expected. Review the incident response plan regularly to ensure it complies with the latest regulations and can handle the ever-evolving threats.

2. Detection and Analysis

This phase involves detecting an incident, determining whether it’s a true positive or a false positive, and understanding its impact. When detection systems are properly configured, incidents trigger alerts, and first responders, usually analysts, receive notifications.

All alerts are not incidents, they could be false positives. Therefore, analysts examine the alert to gain an in-depth understanding of the activity that triggered it. They look at the indicators of compromise (IOCs), threat intelligence, and data from security tools such as SIEM, IDS, and EDR to decide whether an alert is indeed for an incident. If it’s a false positive, analysts add their findings, conclusions, and investigation process into the system, reports, or documentation to improve future detection mechanisms and reduce false positives. If the incident is a true positive, then the analysts determine its extent and scope of impact and inform necessary stakeholders.

3. Containment

Once the security team confirms that the incident is a true positive, they take steps to contain the impact and prevent further spread. You can contain an impacted system by blocking network traffic, disconnecting the system from the internet and from other internal systems, disabling unnecessary and impacted services and software, and airgap the network for further investigation. If an account is compromised, the security team disables the account.

There are two main types of containment:

1. Immediate Containment: Stops the attack and prevents its spread (e.g., disconnecting from the internet, isolating the system).
2. Long-Term Containment: Systematically securing the environment and preventing further damage (e.g., moving the system to a secure environment, updating access controls and firewall rules).

During the containment phase, try to retain as much evidence as possible for further investigation. If no sensitive data resides on the impacted system, it’s tempting to delete everything and reformat and reset the system. However, this is strongly discouraged because it could allow the incident to occur again. One goal of incident response is to mitigate the security loophole to ensure it is not exploited again. Therefore, retaining evidence is crucial.

4. Eradication

After containing the incident, focus on identifying and eradicating its cause. This can involve removing malware, updating security software, such as EDR and anti-malware, updating access controls, applying patches, fixing vulnerabilities, and strengthening and hardening the infrastructure and network of the organization. The goal of this phase is to ensure that any type of infection is cleaned and no threats remain in the environment. When confident that threats are eradicated, verify and test the added security measures to verify the absence of gaps. This phase also gathers evidence to understand the incident better and plan for a more secure future.

5. Recovery

The goal of the recovery phase is to bring the impacted component back to its normal operational state. This involves restoring backups from the last known secure snapshots, verifying the integrity of the component, and restoring disabled software, services, and accounts. Some data, like the data that was written after the component was compromised, might be lost after recovery, but you can fetch that data and move it to the clean component. If you’ve implemented data redundancy, this might help with recovering data. After the system is moved back to the production environment, monitor it for any signs of infection.

6. Lessons Learned

This last phase helps organizations learn from the incident and improve their overall security posture. Document all details of the previous phases. The “good” acts as proof of what worked well and the “bad” points out aspects that need improvement. This phase not only helps organizations understand what they can do better from a security standpoint but also helps individuals learn how to handle incident response situations better. Use these learnings to improve your incident response plan.

These are the major 6 phases of incident response. You will find different variants of the cybersecurity incident response life cycle as perceived and implemented by different organizations. Let’s look into 2 such common variants concisely:

1. 7-phase variant
2. 5-phase variant

What Is the 7-phase Variant of Incident Response?

The 7-phase variant has the same first 6 phases of the NIST incident response but an additional phase for continuous testing and evaluation.

Continuous Testing and Evaluation

This involves continuously testing the systems and network of the organization and putting the incident response plan to test. This effort helps in staying ahead of the curve by identifying security issues and fixing them before an incident.

What Is the 5-phase Variant of Incident Response?

The 5-phase variant categorizes the phases in a slightly different way. The difference here is that it groups a few phases together, as follows:

1. Preparation
2. Detection and Analysis
3. Containment, Eradication, and Recovery
4. Lessons Learned
5. Continuous Testing and Evaluation

These phases are used by teams within an organization and between an organization and its consultants and/or contractors. There’s another important party involved when an incident occurs: regulatory bodies. Now that we’ve explained what incident response is and how to do it, let’s look into its legal and regulatory aspects.

Legal and Regulatory Considerations

Legal and regulatory compliance is an important part of cybersecurity incident response. Organizations must know which laws and regulations they must comply with to have a better security posture and avoid hefty fines, reputational damage, and legal action.

There are three main categories of regulations:

• Industry Specific: These regulations apply to the organization’s industry. For example, healthcare organizations must comply with HIPAA (Health Insurance Portability and Accountability Act).
• Tools & Technologies: Some regulations may apply depending on the tools and technologies related to an organization’s product or service. For example, the PCI DSS (Payment Card Industry Data Security Standard) applies to organizations handling credit card information.
• Geographical: These regulations primarily apply to organizations or consumers based on location. For example, CCPA (California Consumer Privacy Act) applies to any company processing information of California residents and GDPR (General Data Protection Regulation) applies to companies processing information of EU residents.

Certain laws and regulations also outline which regulatory bodies to notify and within what timeframe, in case of an incident. Inform the authorities as early as possible. Sometimes you must work with authorities to resolve the incident. By staying up-to-date with the latest laws and regulations, organizations can integrate compliance when creating a strategic incident response plan.

Although the incident response life cycle is a great framework for organizations to follow and the internet also has a lot of information on the topic, incident response still has its challenges.

Cyber Security Incident Response Challenges

Cyber security incident response challenges are classified as a variety of problems that organizations face when dealing with their networks, systems, data, and cyber threats. It may also introduce vulnerabilities associated with evolving technologies and rapid updates. The top cyber security incident response challenges are:

#1. Volume and Complexity of Attacks

The volume and complexity of cyberattacks increase day by day. This makes it difficult for detection systems to detect incidents in a timely manner. To keep up, organizations must stay up-to-date and use current hardware standards. The fast growth of cyberattacks means delaying upgrades for even a minute opens your organization to devastating threats. The sheer volume of attacks adds a lot of noise that can slow down detection and investigation.

#2. Advanced Persistent Threats (APTs)

APTs often use sophisticated techniques to breach a system or network. According to VMWare, an average APT breach takes 150 days to discover. Because APTs focus on stealth and long-term presence in the network, we rarely see obvious abnormal behavior or anomalies until something goes down. Thus, detecting the initial breach poses a challenge to it might look like usual activity to the eyes of analysts.

#3. Insider Threats

Insider threats are one of the most difficult to detect. Employees often have access to sensitive data and business-critical systems. They’re also aware of the internal architecture and processes and could have knowledge about security measures. Whether with malicious intent or unintentional, incidents caused by an insider can be difficult to differentiate from the normal, unless, of course, they’re very obvious. Insiders can also easily identify loopholes and exploit them stealthily.

#4. Zero-Day

Security tools do not effectively detect zero days in time because the amount of information to detect and mitigate them is limited. Incident response teams can find it challenging to understand the impact of these threats and how to contain them effectively. A lack of obvious clues means it might take more time for incident response teams to respond to and contain this type of incident, which creates a high risk of damage.

#5. Resource Constraints

A quality incident response requires skilled professionals, tools, and dedicated teams/individuals. Thus, incident response is an expensive proposition for an organization that many companies can’t afford. No company wants resource constraints to leave them with security weaknesses and poor incident responses, so they do what they can. Unfortunately, sometimes that’s not enough and companies sometimes have to deal with major damage from an incident.

#6. Co-ordination Across Teams and Departments

Incident response isn’t a single person’s or single team’s job. Various stakeholders from different teams play an important role in a successful and effective incident response. However, communication and collaboration can be challenging, especially when priorities and mindsets differ across stakeholders.

Incident response has challenges like any other process. By following some best practices, you can overcome the challenges and make the best use of incident response.

Cyber Security Incident Response Best Practices

Here are the best cyber security incident response measures for organizations:

#1. Solid incident response plan (IRP)

An extensive incident response plan is the key to an effective incident response. Make sure you understand what your incident response plan requires well before you create a plan. Conduct vulnerability and risk assessment, know the type of threats impacting your organization, and research tools and techniques to mitigate them. The incident response plan should be detailed and extensive. Clearly outline the roles and responsibilities of each individual and team, SOPs, and communication and escalation protocols. Regularly test and update the incident response plan as needed.

#2. Dedicated Incident Response Team (IRT)

While incident response is a collaborative effort, the incident response team (IRT) is the primary responder. Some organizations might assign incident response duties to existing employees who primarily handle other projects. This is not ideal because the priorities and expertise of these members can impact the quality of incident response. Businesses should have a dedicated incident response team with assigned roles and responsibilities(e.g.,: incident manager, team lead, security analysts). Trained and incident response specialists will help you make incident response timely and effective.

#3. Proactive Threat Hunting

If you’re waiting for an incident to happen and before you address it, it’s already too late. Organizations should put effort into avoiding incidents, not just responding to them. You can achieve this with proactive threat hunting, which means actively searching for threats in your organization and mitigating them.

#4. Continuous Monitoring and Detection

Threats to any organization are a constant. Threat actors around the world are continuously trying to exploit security weaknesses, and you can never know when one of yours will be exploited. Therefore, you should continuously monitor traffic and have detection systems in place to catch any suspicious activity. You should also regularly evaluate your approach to monitoring and detection and regularly upgrade them to keep up with the threat actors.

#5. Leveraging Threat Intelligence

Cyber threat intelligence (CTI) gathers data related to known attack patterns. It helps you stay updated with the latest threats, vulnerabilities, IOCs, tactics, techniques, and procedures TTPs (tactics, techniques, and procedures of threat actors). Integrating this intelligence within your monitoring and detection systems can help identify incidents sooner.

#6. Awareness and Training

There’s something new in the cybersecurity world every day. Therefore, employees need to stay aware of the latest tools, techniques, vulnerabilities, and mitigation strategies. You should encourage your security professionals to read cybernews and write-ups, take cybersecurity courses, and earn certifications. Information sharing, training, and hands-on exercises are important. Awareness and training are not just for security professionals; Basic knowledge is crucial for all employees. Employees should know how to identify suspicious activity, whom to report it to, and what actions to take (or not to take) to address it.

#7. Regular Testing and Drills

Conduct regular tests and drills on different aspects of your incident response. Use various scenarios, evaluate the teams on how they respond to them, and see where they can improve. This helps upskill your incident response team and improves collaboration.

#8. Playbooks and Automation

Since incident response has time-sensitive components, use playbooks (documents with guidelines on how to handle an incident) and automation. These help you speed up your incident response. While automation takes care of repetitive, clearly defined tasks, incident responders can work on more complicated tasks.

#9. Compliance

Determine which laws and regulations you need to comply with and make sure you comply with them. This not only helps you avoid fines and legal actions but also lets you improve your security posture. Have a compliance officer or a compliance team regularly review and audit your compliance.

These best practices can help you overcome the challenges and optimize the incident response processes.

While creating or revamping an incident response strategy, you might have some questions. The following section covers the most common questions and answers about cybersecurity incident response.

Wrapping up

Cybersecurity incident response planning lays the foundation for future defenses and is a vital component in every organization. Security leaders should never assume that similar incidents could never happen again. It is important to ensure continuous improvements and build resilience by working on your incident response strategy. Platforms like SentinelOne are very helpful in that regard.

FAQs

What tools are used in incident response?

The types of tools commonly used in cyber security incident response are:

• Security Information and Event Management (SIEM): Centralizes data from logs and alerts
• Endpoint Detection and Response (EDR): Monitors and responds to suspicious activity on endpoint devices
• Threat Intelligence Platforms: Aggregate threat data and known attack patterns from past incidents to provide context on known vulnerabilities and attackers
• Intrusion Detection and Prevention Systems (IDPS): Monitor network or system activities for malicious behavior and block potential attacks
• Security Orchestration, Automation, and Response (SOAR): Automates repetitive tasks, improves response time, and manages incident workflows
• Vulnerability Scanning Tools: Identify vulnerabilities that attackers could exploit
• Forensic Analysis Tools: Analyze compromised systems, recover data, and understand how the breach occurred

Who should be involved in an incident response team?

The designation in an incident response team can vary from one organization to another depending on their strategy. However, for an efficient and successful incident response, the following roles are important:

• Incident Response Manager: Leads the incident response to ensure efficient execution of tasks and adherence to the incident response plan
• Security Analyst: Analyzes and investigates security alerts, identifies threats, and works to mitigate incidents
• IT Specialist: Responsible for containment and remediation, such as isolating compromised systems and restoring operations
• Forensic Analyst: Collects and examines evidence to understand how the breach occurred
• Legal Advisor: Provides legal guidance and advice on action plan, liabilities, and consequences during incident response
• Public Relations Manager: Manages external communications during and after an incident to preserve the organization’s reputation and ensure transparency
• Compliance Officer: Ensures that the response aligns with industry standards and regulations.

What is the difference between incident response and disaster recovery?

Incident response focuses on detecting, investigating, and containing a cyberattack. The goal is to contain and minimize damage and restore the systems to the status quo as soon as possible. It’s about how we handle a cyberattack and recover from it.

Disaster recovery is the process of restoring normal operations after a disruption such as a natural disaster or major system failure. It focuses on restoring full business operations to normal and recovering data.

Given the number and complexity of cyberattacks in today’s age, organizations are always at risk of a cybersecurity incident. Always stay up-to-date and equipped with the latest tools, techniques, and processes to handle incidents. Effective incident response is crucial to contain and minimize damage caused by attacks. Don’t blindly follow an existing framework. Carefully evaluate your needs and customize incident response accordingly. By taking a proactive approach and continuously evaluating and your incident response strategy, your company can improve its ability to respond to incidents effectively and significantly reduce their impact.

In this post, we first defined the incident response concept, the different phases of the incident response life cycle, and the legal and regulatory considerations. We then looked at the challenges organizations face when implementing incident response and best practices to help you overcome them.

SentinelOne can help with your incident response efforts. Check out:

• SentinelOne Singularity XDR integrates multiple security data points for better visibility and automated detection and offers real-time threat detection and automated remediation
• SentinelOne Vigilance MDR provides 24×7 monitoring by expert analysts, manages incidents, conducts deep analysis, and guides businesses through remediation efforts.
• SentinelOne Singularity Threat Intelligence provides a thorough understanding of your threat landscape by monitoring emerging threats to proactively mitigate risks and identify attackers in your environment.