Week 21, 2025 security incident report
Hacking and data breach incidents newly reported 2025.05.19 ~ 05.25
From May 19 to 25, 2025, three new incidents were recorded in South Korea, with a hack that leaked the personal data of 37,000 people standing out the most in terms of scale. Also included were a case in which a personal data leak by an employee of the Korean Federation of Teachers' Associations led to People Power Party appointment certificates being sent to teachers, and a case highlighting how it differed from the cyberattack on LG Uplus. Incident types overall were concentrated in personal data leaks (26) and hacking/intrusion (23), and chain-reaction damage spreading from Radiology Chartered to Pinehurst Radiology Associates was also identified. Overseas, of 54 new incidents, a ransomware attack on Kettering Health that leaked the data of 1.7 million people and disrupted treatment and procedures drew attention, and the exposure of some 184 million login credentials for online services also stood out.
By type
- Data breach26
- Hacking & intrusion23
- Ransomware5
- Malware1
- Phishing & smishing1
- DDoS1
Key incidents in South Korea
Hack leaks personal data of 37,000 people
37KImpact: Personal information of 37,000 people
Personal information of 37,000 people was leaked in a hack. Concerns were raised that many victims were unaware they had been affected.
Read on OhmyNews ↗Differences from the LG Uplus cyberattack examined
The differences between the LG Uplus cyberattack and another incident were examined. The incident being compared, the specific attack method, the scale of the damage and response measures have not been confirmed.
Read on 톱데일리 ↗KFTA staffer leaks personal data used to send teachers People Power Party appointment letters
Impact: Teachers' personal information
An employee of the Korean Federation of Teachers' Associations leaked personal information. The leaked personal information was used to send People Power Party letters of appointment to teachers.
Read on 한겨레 ↗
Supply-chain breaches
Lawsuit investigation into Radiology Chartered data breach
A data breach occurred at Radiology Chartered. A related lawsuit investigation was announced, and the scale of the damage and the date of the incident have not been confirmed.
Read on ClassAction.org ↗
Key incidents in other countries
Ransomware attack on Kettering Health disrupts care and exposes data
1.7MImpact: Data of 1.7 million people exposed; disruption to care and procedures
Kettering Health in Ohio, United States, was hit by a ransomware attack, causing a system-wide outage and disrupting care, including the cancellation of non-emergency procedures. While systems were being restored, scam calls targeting patients were also identified. A class action lawsuit was subsequently filed, and the data breach was confirmed to have affected 1.7 million people.
Related reports: 31 · last report →184 million login credentials for multiple online services exposed
184MImpact: About 184 million login credentials
A database containing about 184 million login credentials for multiple online services was exposed online. The exposed data included login details and passwords for Apple, Google, Facebook, Microsoft and others. Apple ID login details were exposed unencrypted.
Related reports: 16 · last report →UK Legal Aid Agency hack leaks personal and financial data
250KImpact: Personal data of hundreds of thousands of people, plus about 250,000 pre-2007 records and probation-related information later confirmed
The UK Legal Aid Agency was hit by a cyberattack that exposed the personal data of hundreds of thousands of people and took systems offline. Changes to the interim legal aid scheme were announced afterwards. Further investigation in 2026 revealed that about 250,000 records from before 2007 and probation-related information had also been stolen, with the oldest data dating back to 1978.
Related reports: 13 · last report →Hack of Adidas third-party customer service provider leaks customer data
Impact: Customer personal information leaked; number of affected people unconfirmed
A third-party customer service provider for Adidas was hacked, leaking customers' personal information. Adidas disclosed the breach and said credit card information was not leaked. The number of affected customers and whether US and EU customers were included have not been confirmed.
Related reports: 10 · last report →LexisNexis Risk Solutions breach exposes data of 364,333 people
364.3KImpact: Personal information of 364,333 people
Personal information of 364,333 people connected to LexisNexis Risk Solutions was leaked. The attacker accessed GitHub using a stolen company account and took names, contact details, Social Security numbers, driver's license numbers, dates of birth and other data. The company disclosed the breach and notified customers.
Related reports: 9 · last report →