When a cyber attack strikes, the first 24 hours can feel like chaos. Systems may be locked down, staff are scrambling for answers, and leadership is worried about damage to operations and reputation. Yet, this window is also the most critical. How your business responds in those first few hours often determines whether the incident becomes a short-lived disruption—or spirals into a full-blown crisis.

For organisations in Australia, where cybersecurity threats continue to rise against both enterprises and SMEs, a well-structured incident response plan is no longer optional. Between ransomware, phishing campaigns, and increasingly complex risks like adversarial AI attacks and LLM security vulnerabilities, attackers are moving faster than ever. The good news? With preparation and a clear playbook, businesses can take control of the situation before it controls them.

This guide breaks down what to do in the crucial first 24 hours of a cyber incident, from detection to recovery, while highlighting why preparedness is key to achieving true cyber resilience for SMEs and enterprises alike.

The First 24 Hours of Incident Response

Here’s a snapshot of the critical steps every Australian business should follow in the immediate aftermath of a cyber attack:

1. Detect and Confirm the Incident – Spot unusual activity, validate alerts, and confirm whether it’s a real attack.
2. Contain the Threat – Isolate infected systems, disable compromised accounts, and stop attackers from spreading further.
3. Communicate Internally – Provide clear instructions to staff and ensure decision-making authority is established.
4. Preserve Evidence – Secure logs, files, and data that will support forensic analysis and compliance requirements.
5. Notify Stakeholders – Keep leadership, regulators, insurers, and affected customers informed in a timely manner.
6. Begin Recovery – Restore systems safely, validate backups, and focus on both operational and reputational recovery.

With this roadmap in place, let’s dive deeper into how each of these steps plays out in practice—and why they matter for long-term resilience.

Step 1: Detect and Confirm the Incident

The first step is simply knowing that something has gone wrong. Cyber attacks aren’t always obvious; they may present as unusual login attempts, unexplained data transfers, or sudden system slowdowns. The earlier a potential breach is detected, the better the chances of limiting damage.

Businesses should rely on continuous monitoring tools, security alerts, and staff vigilance. Many incidents are spotted not by IT teams but by employees noticing suspicious emails or system behaviour. This is why phishing simulations and awareness training matter—staff are more likely to report suspicious activity quickly if they’ve practised recognising it.

Once suspicious activity is flagged, it’s critical to confirm whether it’s a real incident. False positives can waste valuable time, while false negatives can allow attackers to dig deeper into systems.

Step 2: Contain the Threat

After confirming an attack, the immediate priority is containment. This means limiting the attacker’s ability to move further into your environment. Containment strategies depend on the nature of the threat, but may include:

• Isolating affected devices from the network.
  
• Disabling compromised accounts.
  
• Blocking malicious IP addresses or domains.
  
• Segregating critical systems from non-essential ones.
  

For example, during a ransomware response, disconnecting infected endpoints from the broader network can prevent the encryption from spreading company-wide. Speed is crucial here—the longer the attacker has access, the greater the potential damage.

Step 3: Communicate Internally

Clear and timely communication is essential. Chaos thrives on silence, and without guidance, employees may panic, speculate, or unintentionally worsen the situation.

Internal communication should cover:

• Who has authority to make decisions.
  
• What employees should do (or avoid doing).
  
• Which systems are off-limits until further notice.
  

This is where having a predefined incident response plan in Australia makes all the difference. Teams know exactly what their roles are, and communication flows efficiently without guesswork.

Step 4: Preserve Evidence

It’s tempting to immediately start fixing things, but preserving evidence is just as important as patching the hole. Logs, emails, malicious files, and even screenshots can help forensic teams understand what happened, how it happened, and how to prevent a repeat.

Preserving evidence also has legal and compliance implications. For organisations working towards Essential 8 compliance or other frameworks, proper evidence handling is critical for audits and potential law enforcement investigations.

Step 5: Notify Stakeholders

Not every incident requires public disclosure, but many do involve notifying key stakeholders. This may include:

• Senior leadership and board members.
  
• Affected customers or clients.
  
• Regulators (depending on industry requirements).
  
• Insurance providers.
  

The goal is not to alarm but to keep stakeholders informed and demonstrate that the situation is under control. Transparency builds trust—even when the news isn’t good. Failing to notify stakeholders promptly can result in reputational damage and regulatory penalties.

Step 6: Begin Recovery

Once the threat has been contained and evidence secured, focus shifts to recovery. This involves restoring systems, ensuring backups are clean, and monitoring closely for signs of reinfection.

For many organisations, recovery also includes negotiating or managing fallout from ransomware, rebuilding damaged systems, or even engaging with external cybersecurity firms for specialised support.

Recovery is not just technical. It includes reputational repair, customer reassurance, and rebuilding internal confidence that operations can safely continue.

The Importance of Preparedness

The steps above may sound straightforward, but in practice, businesses without preparation often struggle to execute them effectively. Without predefined playbooks, staff waste time figuring out who’s in charge, which slows down containment. Without employee training, phishing emails slip through unnoticed. Without tested backups, recovery drags on for weeks.

Preparedness means having:

• A documented incident response plan in Australia tailored to your business.
  
• Regular drills and simulations to test readiness.
  
• Continuous education on evolving threats, from ransomware to adversarial AI risks.
  
• Strong policies for device usage, authentication, and data handling.
  

Preparedness isn’t about eliminating every possible threat—it’s about ensuring your business can respond quickly, limit damage, and bounce back stronger. That’s the essence of cyber resilience for SMEs and enterprises.

How Aeora Labs Supports Your Response

At Aeora Labs, we know that time is your most valuable asset in the wake of an attack. That’s why our solutions are designed to strengthen both prevention and response:

• Customised incident response planning aligned with Australian standards.
  
• Phishing simulations and micro-training to make employees your first line of defence.
  
• Ransomware response strategies to contain and recover quickly.
  
• Support for achieving Essential 8 compliance, giving your business a solid foundation for resilience.
  
• Continuous education on emerging threats, including LLM security challenges and adversarial AI tactics.
  

By combining technology with people-focused training, we help organisations transform their response from reactive firefighting to proactive, confident action.

Final Thoughts

The first 24 hours after a cyber attack are critical. Detecting, containing, communicating, and recovering effectively can be the difference between a manageable incident and a catastrophic breach. But success in those hours depends on preparation long before the incident occurs.

Building resilience isn’t about eliminating every risk—it’s about ensuring that when the worst happens, your business can respond with clarity, speed, and confidence.

Aeora Labs is here to help you strengthen your defences, train your people, and craft an incident response plan that works in the real world. Don’t wait for the next attack—contact us today to start building a safer tomorrow.