Incident Response 101: What to Do Following a Security Breach

These days, there is no system that is completely impervious to cyberattacks. It doesn't matter whether it's a small business or a large one; anyone can be affected by a security breach. What is most important is how you react when you are. A timely and well-prepared response can be the difference between maximizing damage and recovering more quickly.

In this blog article, we're going to guide you through Incident Response 101 — a step-by-step primer to take if you find out there's a security breach. Whether you're a student learning about cybersecurity or a practitioner compiling your playbook, this primer will help you know the basics in plain language.

Prefer watching instead of reading? Here’s a quick video guide

What Is Incident Response?

Incident Response (IR) is an organized process for managing and addressing the consequences of a security incident or cyber attack. The aim is to be able to detect the attack rapidly, contain it, minimize damage, recover from the incident, and learn from it in order to avoid future breaches.

The response normally adheres to a lifecycle consisting of six primary stages:

• Preparation
• Identification
• Containment
• Eradication
• Recovery
• Lessons Learned

Let's break each step down.

Preparation: Prior to the Breach

The most critical aspect of incident response occurs prior to the breach even taking place. Preparation is having tools, policies, and teams in place to respond in the event of a cybersecurity incident.

What to do:

• Establish and document an Incident Response Plan (IRP).
• Delegate roles and responsibilities to your IR team.
• Implement monitoring tools such as SIEM (Security Information and Event Management).
• Train employees in phishing awareness, strong passwords, and safe browsing.
• Conduct periodic vulnerability scans and penetration testing.

Example:

When you get an alert from your intrusion detection system (IDS), your team should be clear on what to do and who does what.

Identification: Detecting the Breach

This is the step where you realize that something is amiss. Early detection is critical to containing the scope of the breach.

• Indications of a breach may include:
• Unusual login attempts or patterns
• Unknown processes running on servers
• Files accessed or transferred in bulk
• Systems acting strangely or crashing

What to do:

• Investigate alerts and logs to validate if it's an actual incident.
• Identify the scope, severity, and impact.
• Categorize the type of incident — is it malware, phishing, insider threat, or data breach?

Example:

Your web server logs indicate several login attempts from foreign IPs and unauthorized database queries. That's a red flag.

Containment: Stop the Spread

After you've validated a breach, next is to contain the damage. You want to quarantine the threat so that it does not infect other systems.

There are two kinds of containment:

• Short-term containment: Emergency measures to quarantine affected systems.
• Long-term containment: Stop-gap measures to enable business operations while you fix things permanently.

What to do:

• Disconnect infected systems from the network.
• Reset compromised passwords.
• Implement firewall rules to block malicious IPs.
• Save forensic evidence for investigation.

Example:

If one employee’s laptop is infected with ransomware, disconnect it immediately to stop the spread to other devices.

Eradication: Remove the Threat

After you’ve contained the incident, it’s time to find the root cause and completely remove the threat from your environment.

What to do:

• Identify all affected files, systems, or user accounts.
• Remove malware, backdoors, or unauthorized access.
• Patch vulnerabilities that were exploited.
• Scan systems thoroughly to ensure nothing is left behind.

Example:

If the attacker has exploited your CMS using an outdated plugin, eliminate that plugin and update all things to the newest version.

Recovery: Get Back to Normal

After the threat has been eliminated, you can begin recovering and restoring operations. This phase aims to get systems back online safely without jeopardizing another attack.

What to do:

• Restore data from clean backups.
• Monitor systems for signs of reinfection.
• Restore systems slowly to the network.
• Notify stakeholders, customers, or legal authorities if necessary.

Example:

After recovering from backup, watch your servers for a minimum of 24–72 hours to ensure the threat is removed before returning to normal business.

Lessons Learned: Review and Improve

Most people do not perform this step, but it's the most critical. Post-incident review after the incident to understand what went wrong and how to better protect yourself.

What to do:

• Conduct a "Lessons Learned" meeting with the response team.
• Record what occurred: timeline, actions taken, and impact.
• Modify your Incident Response Plan based on what you've learned.
• Enhance detection and prevention systems.

Example:

If phishing was the initial attack vector, you might choose to begin using email filters or to provide additional employee training.

Additional Tips for Managing Incidents

• Keep calm: Panic can result in errors. Adhere to the plan.
• Communicate effectively: Inform internal and external stakeholders.
• Document everything: Assists with legal compliance, insurance claims, and learning.
• Engage legal & PR teams: Particularly for breaches of personal data or customer information.

Why Every Organization Needs an IR Plan

Not even the most secure organizations like Google, Facebook, or Microsoft have been able to avoid breaches. What distinguished them was the way they responded.

An Incident Response Plan assists you:

• Minimize financial and reputational damage
• Respond quicker and more effectively
• Obey data protection regulations such as GDPR
• Secure customer trust

Final Thoughts

A security breach is stressful — but with the right processes and planning, it doesn't need to be disastrous. By completing the six stages of incident response, you can identify, contain, and bounce back from incidents confidently.

Whether you're a cyber enthusiast, a student, or a pro, learning incident response is an essential skill in your arsenal. The more prepared you are, the better you'll perform whatever comes your way.

Stay safe, stay alert — and keep learning!