The Cyberattack Playbook: What to Do in the First 24 Hours

Hour 1-2: Identify and Contain the Threat

Step 1: Confirm the Attack

Not every security alert indicates a full-scale breach. Before taking action, it is important to verify the incident:

• Review security logs and alerts from firewalls, SIEM tools, or endpoint detection solutions.
• Identify unauthorized access, unusual file modifications, or system behavior changes.
• Consult with an MSSP to analyze the threat and confirm the nature and severity of the attack.

Step 2: Isolate Affected Systems

Once a cyberattack is confirmed, containment is the top priority.

• Disconnect compromised devices from the network to prevent further spread.
• Disable remote access for affected accounts.
• Block known malicious IPs and suspend access to infected systems.
• If ransomware is involved, do not shut down infected systems without forensic consultation.

How an MSSP Can Help:

An MSSP provides real-time threat monitoring and automated containment solutions, ensuring rapid isolation of affected systems before the attack spreads.

Hour 3-6: Assess the Impact and Begin Incident Response

Step 3: Activate the Incident Response Team

Every organization should have a well-defined Incident Response Plan (IRP), including a designated team responsible for handling breaches. The team should:

• Assign roles for investigation, communication, and recovery efforts.
• Review initial findings to determine the scope of the attack.
• Engage an MSSP for forensic analysis and expert guidance.

Step 4: Determine the Scope of the Attack

Understanding how far the breach has spread is critical for containing damage and planning recovery. Key questions include:

• Which systems, applications, or data have been affected?
• Has sensitive customer, financial, or business data been exposed?
• How did the attacker gain access—was it phishing, credential theft, or an unpatched vulnerability?

How an MSSP Can Help:
MSSPs use advanced threat intelligence and security analytics to rapidly assess the scope of an attack, identifying affected systems and attack vectors to guide an effective response.

Hour 6-12: Secure and Begin Recovery

Step 5: Change Credentials and Strengthen Access Controls

Once compromised accounts are identified, security teams should:

• Force password resets for affected users and privileged accounts.
• Enable Multi-Factor Authentication (MFA) to prevent unauthorized access.
• Terminate active sessions to remove potential intruders.

Step 6: Preserve Evidence for Investigation

A proper forensic investigation can uncover the root cause of the attack and inform future security improvements.

• Create forensic backups of compromised systems before making major changes.
• Document key findings, including indicators of compromise (IOCs) and attacker movements.
• Work with legal and compliance teams to determine reporting obligations.

How an MSSP Can Help:
MSSPs offer digital forensics and incident analysis, ensuring all relevant evidence is preserved for regulatory compliance and post-incident review.

Hour 12-18: Communicate with Stakeholders

Step 7: Notify Internal Teams

Organizations need to coordinate their response and ensure key personnel are informed.

• IT, security, and leadership teams should align on messaging and next steps.
• Non-technical departments, such as legal and public relations, should be briefed on how to handle inquiries.

Step 8: Assess Regulatory and Legal Obligations

Certain industries, such as finance and healthcare, have strict breach notification requirements.

• Determine whether regulatory bodies (e.g., the Office of the Privacy Commissioner of Canada) need to be notified.
• If customer data has been compromised, assess whether individuals must be informed.
• Report the incident to law enforcement if the breach involves financial fraud or nation-state actors.

How an MSSP Can Help:
MSSPs provide compliance expertise, guiding organizations through regulatory reporting requirements and minimizing legal risks.

Hour 18-24: Begin Full Restoration and Prevention Measures

Step 9: Restore Systems from Backups

If backups are available, organizations should restore systems carefully to avoid reintroducing malware.

• Verify that backups are clean and unaffected by the attack.
• Restore from a point in time before the breach occurred.
• Prioritize mission-critical systems to minimize downtime.

Step 10: Strengthen Security to Prevent Future Attacks

A cyberattack exposes weaknesses in an organization’s security posture. After recovery, businesses should:

• Implement 24/7 Managed Detection & Response (MDR) to detect future threats in real time.
• Conduct penetration testing and vulnerability assessments to identify security gaps.
• Provide ongoing cybersecurity training to employees, reducing the risk of social engineering attacks.

How an MSSP Can Help:
MSSPs offer continuous security monitoring, proactive threat hunting, and strategic risk assessments to ensure organizations remain protected against evolving cyber threats.

Final Thoughts

Step 9: Restore Systems from Backups

The first 24 hours after a cyberattack are critical. A well-executed response can mean the difference between swift recovery and prolonged business disruption. Key takeaways include:

• Contain the breach quickly to prevent further damage.
• Assess the impact to understand how far the attack has spread.
• Secure credentials and restore operations using verified backups.
• Communicate with stakeholders and meet compliance obligations.
• Strengthen security post-incident to prevent future breaches.

An MSSP can play a vital role in this process, offering expert guidance, real-time threat detection, incident response, and ongoing cybersecurity protection.