Week 15, 2025 security incident report
Hacking and data breach incidents newly reported 2025.04.07 ~ 04.13
From April 7 to 13, 2025, the largest incident in South Korea was the leak of personal data of 1.6 million students of an online course provider. Mass leaks of newsletter email addresses at the Korea Information Security Industry Association also recurred, revealing data leak problems at both an education company and an information security association. Of 44 new incidents overall, personal data breaches were the most common at 32, with hacking/intrusion and ransomware at 6 each. Overseas, the leak of Hertz customers' personal data, driver's license and credit card information, a large-scale data leak at a clinical laboratory, and the exposure of email access at the US Office of the Comptroller of the Currency were reported, and a hack in which crosswalk signals played voices impersonating well-known business leaders also occurred.
By type
- Data breach32
- Ransomware6
- Hacking & intrusion6
Key incidents in South Korea
Online course provider leaks personal data of 1.6 million students
1.6MImpact: Personal information of 1.6 million students
Personal information of 1.6 million students was leaked from an online course provider. The company was fined 50 million won.
Read on KBS 뉴스 ↗KISIA newsletter emails leaked in bulk again
Impact: Bulk leak of newsletter emails
Newsletter emails from the Korea Information Security Industry Association (KISIA) were leaked in bulk. It was a repeat of a leak in January.
Read on 보안뉴스 ↗
Key incidents in other countries
Hertz hack exposes customer personal data and driver's license information
Impact: Customer personal data, including driver's license and credit card information for some customers
Hertz had customer personal data stolen in a 2024 hack. The stolen data included driver's license and credit card information for some customers, and the incident was linked to the Cleo hack. Hertz disclosed the breach, and lawsuits were subsequently filed.
Related reports: 8 · last report →Hacked US crosswalk signals play voices impersonating prominent business leaders
Impact: Impersonating voices played from crosswalk buttons and pedestrian signals
Crosswalk buttons and pedestrian signals in Silicon Valley and the San Francisco Bay Area in the US were hacked to play voices impersonating prominent business leaders. Messages impersonating Elon Musk, Mark Zuckerberg, Jeff Bezos and others were found, and AI-generated voices were used.
Related reports: 8 · last report →Laboratory Services Cooperative breach exposes data of about 1.6 million people
1.6MImpact: Personal information and some financial information of about 1.6 million patients and employees
A network intrusion at Laboratory Services Cooperative in October 2024 led to the theft of personal information of about 1.6 million patients and employees. The stolen data included names, Social Security numbers, medical and test information, and some financial information. In April 2025, legal action over the breach was being considered.
Related reports: 5 · last report →Cyberattack on US clinical lab exposes data of 1.6 million people
1.6MImpact: Information of 1.6 million people
A cyberattack on a US clinical laboratory that provides testing services to Planned Parenthood leaked the information of 1.6 million people. The lab disclosed the breach in April 2025 and urged customers to protect their data. In May, it emerged that some patients remained unaware of the situation months after cybercriminals leaked the test data.
Related reports: 5 · last report →Over 150,000 OCC emails exposed to unauthorized access
150KImpact: More than 150,000 emails from about 100 bank examiners accessible
A breach at the US Office of the Comptroller of the Currency that began in June 2023 compromised an email administrator account. More than 150,000 emails from about 100 bank examiners were accessible, including sensitive information on the supervision of financial institutions. The OCC notified Congress of a major information security incident, and JPMorgan and BNY subsequently limited the information they share with the agency.
Related reports: 5 · last report →