Data breaches have become a constant threat in the digital world, with hackers targeting companies of all sizes and industries. The year 2024 witnessed several large-scale breaches that not only exposed sensitive information but also raised serious questions about cybersecurity readiness. In this blog, we’ll explore the five biggest data breaches of the last year and discuss the valuable lessons every individual and organization can learn from these incidents.
1. National Public Data (NPD) — 2.9 Billion Records Exposed
In August 2024, National Public Data (NPD), a background-check data broker, suffered a staggering breach that exposed nearly 2.9 billion records. The leaked information included full names, Social Security numbers, addresses, and phone numbers from individuals across the U.S., Canada, and the U.K. The aftermath was devastating, with the company filing for Chapter 11 bankruptcy just months later due to lawsuits and regulatory scrutiny. This breach shows the high risk of data brokers, who collect vast amounts of personal data but often lack the security infrastructure to protect it.
2. Ticketmaster and Snowflake Breach — 560 Million Records Leaked
In May 2024, Ticketmaster revealed that approximately 560 million customer records were leaked due to unauthorized access through the Snowflake cloud platform. This data included personal and payment details, which were later found for sale on the dark web. The breach was part of a larger chain of attacks on Snowflake environments affecting multiple companies, including Santander and AT&T. The incident highlights how third-party cloud misconfigurations and vendor dependencies can become critical points of failure for organizations.
3. Change Healthcare Ransomware Attack — 145 Million Patient Records
The healthcare sector was shaken in February 2024 when Change Healthcare, a major medical billing and claims processor, was targeted by the BlackCat ransomware group. Nearly 145 million patient records containing sensitive medical and billing data were stolen. The attack disrupted pharmacy operations nationwide, delaying prescriptions and impacting patient care. This breach revealed how weak network segmentation and lack of ransomware preparedness can lead to not just data loss, but also real-world consequences for millions of people.
4. AT&T Data Leak — 73 Million Customers Affected
In March 2024, AT&T confirmed a data leak affecting 73 million current and former customers. The compromised data included Social Security numbers, account information, and passcodes. Though call and message content remained safe, the breach was significant enough to trigger an FCC investigation and a $13 million settlement. AT&T’s experience underscores the need for constant monitoring of legacy systems and stricter access control policies to prevent long-term undetected vulnerabilities.
5. Snowflake Platform Breach — Widespread Cloud Exposure
The Snowflake breach was one of the most far-reaching attacks of 2024, impacting over 100 companies that relied on its cloud services. The attackers exploited misconfigured environments and over-privileged access, exposing sensitive customer and corporate data. The incident emphasized the importance of secure cloud architecture, regular audits, and zero-trust policies to prevent attackers from exploiting a single weak point to compromise multiple organizations.
Key Lessons We Can Learn
These five breaches reveal that modern cybersecurity is as much about managing third-party risks as it is about protecting internal systems. Companies must implement multi-factor authentication, zero-trust security models, and continuous monitoring of all endpoints and cloud services. Regular security audits, employee training, and proactive incident response planning can significantly reduce the risk of catastrophic data leaks. In today’s interconnected digital ecosystem, a single vulnerability can impact millions of lives—making robust cybersecurity a non-negotiable priority.