Data Breach Guidance: A Practical Guide for Security Teams

FACT: There’s a direct link between the amount of time it takes to identify a breach and the cost of the breach.

According to IBM’s 2023 Cost of a Data Breach Report, organizations that identify and contain a breach within 200 days save an average of $1.1M compared to organizations that take longer.

With the average breach now costing $4.885M, your response time matters.

Are you looking for guidance on what to do after a breach?

In this post, we’ll cover the four data breach response stages as well as some investigation and recovery strategies.

Initial Response (First 24 Hours)

During the first 24 hours after identifying a breach, security teams need to identify and document all indicators of compromise (IoC).

The documentation should include both timestamps and how the IoCs were found.

During this step you need to determine whether the breach is ongoing or contained.

Define the scope of the breach by identifying which systems were affected as well as the potential data exposed.

Create an image of the affected systems (including the dumped memory) before containing the breach.

This ensures that you have forensic evidence to go back to for analysis.

Segmenting your network will help contain the attack without shutting down any compromised systems.

Before revoking any compromised credentials, ensure that they are properly documented.

Based on your incident response plan, you’ll need to notify the relevant stakeholders.

This often includes executive leadership, legal counsel, and public relations teams.

Finally, all members of the incident response team should use encrypted communications that are separate from potentially compromised systems.

Investigation and Assessment (24-72 Hours)

During the investigation phase, the focus is on conducting forensic analysis of all affected systems.

The goal here is to reconstruct the complete attack timeline, identifying initial access vectors and subsequent lateral movement.

Once again, you’ll need to document all malware artifacts, compromised accounts, and affected data assets.

The investigation should determine the exact methods used to gain initial access, exfiltrate data, and the specific information compromised.

In order to understand the impact of the breach, you’ll need to quantify the exposed records and affected individuals.

Based on the compromised data, determine any regulatory implications based on your industry-specific requirements (e.g. GDPR, HIPAA, CCPA).

Remediation and Recovery (72+ Hours)

Before removing any persistent threats from your environment, ensure you’ve applied all the relevant security patches.

Obviously, focus first on the vulnerabilities exploited during the breach.

Implement credential resets across all potentially affected systems and services.

Before restoring systems from backups, verify the integrity of the backup.

Deploy additional security controls to prevent similar compromises in the future.

In terms of notifying external parties of the breach, different stakeholder groups have different requirements.

Use notification templates that comply with regulatory requirements to maximize efficiency.

Create dedicated support channels for anyone affected by the breach.

Long-term Security Enhancement

Post-incident, it’s critical to conduct a thorough analysis of the security failures that enabled the breach.

Where relevant, update security policies and procedures based on the identified gaps.

Improve your monitoring capabilities with a specific focus on detection methods that could have identified the breach earlier.

This may include increasing server logging verbosity as well as logging HTTP POST bodies.

Monitor external sources, including dark web forums, for any signs of exposed data.

Implement automated alerts when any compromised data is detected.

Ensure that multi-factor authentication is required before accessing sensitive systems.

Review your data classification and protection mechanisms, including encryption and data loss prevention.

Conduct regular penetration testing and assumed breach exercises.

Preserve all incident records, investigation findings, and remediation actions in a secure repository.

Maintain detailed compliance records demonstrating your adherence to regulatory requirements.

Prepare incident reports suitable for regulatory bodies, insurance carriers, and external auditors.

Conclusion

The effectiveness of a breach response depends on several factors.

Response speed directly impacts the ability to contain damage and preserve evidence.

Documentation quality affects both the effectiveness of your investigation as well as your ability to demonstrate compliance.

Security teams should regularly test and update their incident response plans based on new threats and organizational changes.

Conduct periodic tabletop exercises to validate response procedures.

Update contact lists and escalation procedures quarterly.

Review and update technical response capabilities based on new attack techniques and available security controls.