The First 24 Hours After a Cyber Attack are Crucial

When a cyber attack hits, the clock starts ticking. How your organisation responds in the first 24 hours determines whether the incident is urgently contained or spirals into weeks of disruption, financial loss and reputational damage.

The organisations that come out stronger after a cyber attack aren’t always the ones who dodge an attack. They are the ones who have a plan.

The role of a Cyber Incident Response Plan as Best Defence

A Cyber Incident Response Plan is like a fire drill for your business. When everyone in your organisation knows their role and steps are clear, you can respond to incidents almost instantly. No scrambling, no confusion, just quick action.

With a plan in place:

• Roles and responsibilities are clear.
• Communications are pre-drafted.
• Technical steps are rehearsed.

What to Do in the First 24 Hours

In case an attack slips through or if you don’t have a formal plan yet, there are urgent steps you should take in those critical first 24 hours…

1. Contain the Damage Immediately: Disconnect affected devices, lock compromised accounts and limit access. The goal is to stop the attack from spreading throughout the organisation.
2. Call in the Experts: If you don’t have internal security specialists, bring in your IT Partner or Managed Service Provider (MSP). The earlier cyber specialists are involved, the faster you’ll contain the threat.
3. Preserve Evidence: Don’t rush to wipe everything clean. Document the timeline, keep logs and capture evidence. This helps with investigation, recovery and compliance.
4. Communicate with Leadership: Executives and decision makers need to be updated quickly. But don’t make public statements until facts are verified. Inaccurate information can cause more harm than the incident itself.
5. Meet Compliance Obligations: In Australia, cyber incidents may need to be reported under the Notifiable Data Breaches Scheme via the Office of the Australian Information Commissioner (OAIC) and in certain cases to the Australian Cyber Security Centre (ACSC). Proper documentation is critical, not just for regulators but for insurers, legal defence and building trust with customers. Failing to meet reporting requirements can add legal and financial penalties to an already costly event.
6. Prioritise Critical Operations: Identify what your business cannot live without. These can be customer transactions, patient care systems, or production lines. Focus on what keeps operations running.
7. Begin Recovery, Carefully: Work with your internal IT team or MSP to restore systems from clean backups only after they’ve been verified safe. Bringing compromised systems back online too soon risks undoing all containment efforts.
8. Debrief and Plan Forward: Once the immediate crisis is contained, hold a review. Ask: “What failed, what worked, and what needs to change?” This is where a formal Cyber Incident Response Plan becomes not just a best practice, but a business necessity.

Why Urgency and Being Prepared Matters

Cyber criminals don’t wait, and regulators won’t either. Every minute of delay increases the damage and every missed compliance obligation increases your liability. The first 24 hours are about decisive action: contain, document, report, and recover.

Preparation isn’t just about technology but also about culture. This is exactly what the Australian Government is highlighting in Cyber Security Awareness Month this October. With its theme “Building our cyber safe culture,” the focus is on the everyday practices that make the biggest difference when an attack happens.

The weekly topics including improving event logging, phasing out legacy technology, and managing supply chain risks aren’t just theoretical discussions, they are the foundations that determine how well your organisation can respond under pressure.

Cyber Awareness Month is a timely reminder that a strong culture of awareness and being prepared is your best defence not just for October, but year-round and into the future.

How Diamond IT Can Help

The first 24 hours of a cyber attack can shape everything, from operational impact to compliance exposure and reputational fallout. Without a clear plan, those hours can feel overwhelming.

But resilience doesn’t start after an incident. It starts now.

At Diamond IT, we help you build confidence before the crisis hits. A strong Cyber Incident Response Plan, combined with a culture of awareness, ensures your team knows exactly what to do when it matters most.

Whether you’re starting from scratch or looking to strengthen your current plan, our experts are here to help you prepare, respond swiftly, and meet your obligations with confidence.

👉 Let’s build your response plan together. Reach us via phone at  1300 307 907, email us at enquiries@diamondit.com.au or fill out the form below.