What Your IT Team Should Do Within the First 24 Hours of a Breach

When a cybersecurity breach happens, the clock starts ticking immediately. In the first 24 hours, your response can either contain the daage, or make things worse. For growing businesses in highly regulated industries like healthcare, the stakes are even higher. Delayed or mishandled response efforts can mean data exposure, compliance violations, service interruptions, and long-term reputational damage.

Yet, many small and mid-sized companies aren’t ready. A 2023 IBM report found that it takes an average of 204 days to identify a breach and 73 days to contain it. For companies without a dedicated security team, that timeline can stretch even longer. The first 24 hours are the most critical, but without an incident response plan, even experienced internal IT teams can find themselves scrambling.

In this guide, you’ll learn exactly what your IT team should be doing in the first 24 hours after a breach. We’ll cover essential incident response plan steps, from identifying the breach to post-breach containment, and explain how each action affects your operational resilience.

Common Challenges Businesses Face After a Breach

Slow Detection and Delayed Action

Many breaches go unnoticed for weeks. Once discovered, internal teams often delay action while trying to confirm what happened, escalating only after serious damage is already done.

Lack of a Documented Incident Response Plan

Without a tested cyber incident response checklist, teams have to improvise. This creates confusion about who’s responsible for what—and slows everything down.

Fragmented IT Resources

In many growing companies, IT responsibilities are distributed across generalists, contractors, or outsourced vendors. When a breach occurs, coordination between these parties is inconsistent, leading to missed steps in the breach response timeline.

Compliance Pressure

In healthcare, the first 24 hours after a cyberattack are critical for HIPAA and other regulatory notifications. Failure to act quickly can result in fines, audits, and increased scrutiny.

What Your IT Team Should Do Within the First 24 Hours of a Breach

1. Contain the Breach Immediately

What it is: This means isolating affected systems to prevent further spread. Disconnect compromised machines from the network, revoke user credentials if needed, and stop unauthorized data flows.

Why it matters: Containment stops the attacker’s access. The longer a threat actor stays active in your environment, the more damage they can do.

How to implement: Ensure firewalls, endpoint detection systems (like XDR), and network monitoring tools are configured to support rapid isolation. Your IT response to cybersecurity incidents should include predefined containment actions in your incident response plan.

2. Start Preserving Evidence

What it is: Begin collecting logs, system snapshots, and relevant forensics. Don’t delete or wipe affected systems unless absolutely necessary.

Why it matters: This step is crucial for identifying what happened, how it happened, and whether sensitive data was accessed or exfiltrated.

How to implement: Work with a security partner or internal specialist to preserve volatile data. Use secure storage to avoid contamination and ensure chain-of-custody if legal action is required later.

3. Notify Internal Stakeholders

What it is: Communicate the breach to leadership, legal, compliance, and other affected business units.

Why it matters: Early transparency ensures the organization can make timely decisions. Delayed notification leads to misaligned messaging and reactive legal exposure.

How to implement: Create predefined communication templates as part of your incident response plan. Share only verified information and update as facts become clear.

4. Begin Initial Forensic Analysis

What it is: Start identifying how the attacker got in, what systems were accessed, and what data may be affected.

Why it matters: Early forensic insight helps prioritize response efforts and informs regulatory disclosures.

How to implement: Use endpoint detection platforms and SIEM logs to trace activity. If your team lacks in-house capability, escalate to an incident response partner with breach investigation experience.

5. Review Regulatory Reporting Obligations

What it is: Assess whether the breach meets legal thresholds for external reporting to customers, regulators, or partners.

Why it matters: Especially in healthcare, data breach emergency response efforts must align with HIPAA, HITECH, and potentially state-level privacy laws.

How to implement: Keep an updated compliance map. Work with legal counsel to determine which disclosures are required and when. Document all decisions and actions.

Preparing for the Next 24 Hours (and Beyond)

Most companies focus on stopping the bleeding, but few take the time to prepare for the next wave of consequences. A well-executed initial breach response is only part of the equation. Recovery planning, external communications, and long-term remediation are just as important.

For healthcare organizations and other regulated industries, the risk isn't just data loss—it’s loss of trust. Cybersecurity isn't just an IT issue. It’s a business risk with operational, legal, and financial consequences.

If you’re not confident in your current breach response timeline or incident response plan steps, now is the time to evaluate. Because when the next breach happens—and it will—24 hours can define your next 24 months.

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