1. Equifax Data Breach (2017)

Incident Overview:

• Affected Individuals: Approximately 147 million.
• Data Compromised: Social Security numbers, birth dates, addresses, and in some cases, driver’s license numbers and credit card information.
• Cause: Exploitation of a known vulnerability (Apache Struts) that had not been patched.

Lessons Learned:

1. Timely Patch Management:
   • Organizations must promptly apply patches and updates to known vulnerabilities to prevent exploitation.
2. Regular Security Audits:
   • Conduct regular security audits and vulnerability assessments to identify and mitigate risks.
3. Incident Response Plan:
   • Develop and regularly test a comprehensive incident response plan to ensure swift action in the event of a breach.
4. Data Encryption:
   • Encrypt sensitive data both at rest and in transit to protect it from unauthorized access.

2. Target Data Breach (2013)

Incident Overview:

• Affected Individuals: Approximately 40 million payment card records and 70 million customer records.
• Data Compromised: Payment card numbers, expiration dates, CVV codes, and customer contact information.
• Cause: Attackers gained access through a third-party HVAC contractor and exploited weaknesses in Target’s network segmentation.

Lessons Learned:

1. Third-Party Security:
   • Implement stringent security measures and regular audits for third-party vendors.
2. Network Segmentation:
   • Use network segmentation to isolate sensitive data and systems, reducing the risk of lateral movement by attackers.
3. Continuous Monitoring:
   • Employ continuous monitoring and advanced threat detection systems to identify and respond to suspicious activities.
4. Employee Training:
   • Conduct regular security awareness training to help employees recognize and respond to potential threats.

3. Yahoo Data Breaches (2013-2014)

Incident Overview:

• Affected Individuals: Over 3 billion user accounts (2013) and 500 million user accounts (2014).
• Data Compromised: Names, email addresses, telephone numbers, dates of birth, hashed passwords, and in some cases, encrypted or unencrypted security questions and answers.
• Cause: State-sponsored actors exploited weak security measures and accessed Yahoo’s user database.

Lessons Learned:

1. Advanced Threat Detection:
   • Implement advanced threat detection and prevention systems to identify and mitigate sophisticated attacks.
2. Password Management:
   • Use strong, unique passwords and multi-factor authentication (MFA) to secure user accounts.
3. Data Minimization:
   • Minimize the amount of sensitive data stored and regularly review and purge unnecessary data.
4. Transparent Communication:
   • Maintain transparent and timely communication with affected individuals and stakeholders during a breach.

4. Marriott International Data Breach (2018)

Incident Overview:

• Affected Individuals: Approximately 500 million.
• Data Compromised: Names, mailing addresses, phone numbers, email addresses, passport numbers, and other personal information.
• Cause: Unauthorized access to the Starwood guest reservation database, which had been compromised since 2014.

Lessons Learned:

1. Due Diligence in Mergers and Acquisitions:
   • Conduct thorough security assessments and due diligence during mergers and acquisitions to identify and address existing vulnerabilities.
2. Proactive Security Measures:
   • Implement proactive security measures such as intrusion detection systems (IDS) and regular penetration testing.
3. Data Encryption:
   • Encrypt sensitive data to protect it from unauthorized access, even if the database is compromised.
4. Comprehensive Logging and Monitoring:
   • Maintain comprehensive logging and monitoring to detect and respond to suspicious activities in real-time.

5. Capital One Data Breach (2019)

Incident Overview:

• Affected Individuals: Approximately 100 million in the U.S. and 6 million in Canada.
• Data Compromised: Names, addresses, phone numbers, email addresses, dates of birth, and self-reported income.
• Cause: Exploitation of a misconfigured web application firewall (WAF) on AWS (Amazon Web Services).

Lessons Learned:

1. Cloud Security:
   • Implement robust cloud security practices, including proper configuration management and regular security assessments.
2. Access Controls:
   • Use least privilege access controls to limit user permissions and reduce the risk of unauthorized access.
3. Continuous Security Training:
   • Provide continuous security training to employees to ensure they are aware of the latest security practices and threats.
4. Incident Response Readiness:
   • Ensure incident response teams are well-prepared and equipped to handle breaches promptly and effectively.