Week 25, 2026 security incident report
Hacking and data breach incidents newly reported 2026.06.15 ~ 06.21
From 15 to 21 June 2026, nine new incidents were recorded in South Korea, with the leak of personal data and startup ideas of 5,000 successful applicants to Modu-ui Changeop (Startup for Everyone) drawing the most attention. The routes of data leaks were also diverse, including the leak of access credentials for some 500 GitHub accounts and authentication keys of about 30 companies, and a police officer leaking personal data for money. Ransomware damage at semiconductor cleaning company KoMiCo, signs of hacking and concerns over a leak of design drawings at Daechang Solution, and real estate app outages caused by the blocking of a Ministry of the Interior and Safety relay server followed, and chain damage spreading from Day1 Company to Samsung Electronics was also confirmed. Overseas, 50 new incidents were recorded, with notable cases including the leak of information on more than 3 million Texas licence holders, the online exposure of 24 billion stolen records, and data breaches and chain damage at healthcare institutions.
By type
- Data breach41
- Hacking & intrusion10
- Ransomware4
Key incidents in South Korea
Personal data and startup ideas of 5,000 "Everyone's Startup" winners leaked
5kImpact: Personal information and startup ideas of 5,000 successful applicants
It was revealed that in June 2026, personal information and startup ideas of 5,000 successful applicants were leaked from the "Everyone's Startup" platform. The hacker was identified as a company participating in the project. The Ministry of SMEs and Startups completed blocking measures and apologised, and said it would support proof of original authorship of the ideas. Police opened a preliminary inquiry into how the leak occurred.
Related reports: 65 · last report →Personal and start-up data of 5,000 successful Modu-ui Changeop applicants leaked
5kImpact: Email addresses, assessment comments and start-up idea summaries of 5,000 successful applicants
In June, the personal information of all 5,000 successful applicants on the Modu-ui Changeop (Startup for All) platform was leaked. An investigation confirmed that email addresses, assessment comments and summaries of start-up ideas were within the scope of the leak, and it also emerged that non-public information contained in the API had been collected along with encryption keys. Han Seong-sook apologised and pledged measures to protect ideas, and the personal information collection policy was overhauled to a step-by-step collection method. Police opened a preliminary investigation and then raided four locations, including an AI solutions company.
Related reports: 23 · last report →Access credentials for some 500 GitHub accounts leaked
Impact: Access credentials for some 500 GitHub accounts and authentication keys for some 30 companies leaked
In July, the leak of access credentials for some 500 GitHub accounts and authentication keys for some 30 companies was reported. South Korean police first detected the leak and launched an investigation. Concerns were raised about further personal data breaches stemming from leaked access tokens for development environments.
Related reports: 7 · last report →Semiconductor cleaning company KoMiCo hit by ransomware
Semiconductor cleaning company KoMiCo was hacked in a ransomware attack. Concerns were raised about the leak of semiconductor technology and knock-on damage to the supply chain. Whether technology was actually leaked, the scale of the damage and the response measures have not been confirmed.
Related reports: 3 →Police officers leaked personal data to private investigators for money
Police officers leaked personal data and internal police information to private investigators in exchange for money. In June, a police officer who had looked up and leaked personal data without authorisation was arrested and referred to prosecutors. In July, five people, including two serving police officers, were charged.
Related reports: 3 · last report →Signs of hacking at Daechang Solution raise fears of patent and design drawing leaks
Signs of hacking emerged at Daechang Solution. There are concerns that patents and design drawings may have been leaked.
Read on 뉴스저널리즘 ↗Cyber-attack blocks Interior Ministry relay server, disrupting property app
Impact: Service outage at a property transaction price app
A cyber-attack caused a relay server of the Ministry of the Interior and Safety to be temporarily blocked. As a result, a property transaction price app suffered a service outage.
Read on Chosunbiz ↗KISED, hit by data leak, had 15 shortcomings in previous year's security audit
A personal data leak occurred at the Korea Institute of Startup & Entrepreneurship Development (KISED). KISED had been cited for 15 shortcomings in a 2025 security audit.
Read on 산경투데이 ↗
Supply-chain breaches
Day1 Company hack leaks students' and instructors' personal data
In June 2026, personal data was leaked in a hack of Day1 Company, the operator of Fast Campus, and damage to information on instructors and employees of Samsung, LG and Kakao was also confirmed. The leaked items included passwords and phone numbers, and a further leak of card and account information later came to light. Day1 Company said early on that it was assessing the scale of the damage, and criticism was later raised over its response and lack of communication.
Related reports: 11 · last report →
Xsolis data breach affects at least 9 healthcare systems and 1.4 million patients
1.4mImpact: At least nine healthcare systems and 1.4 million patients
Healthcare artificial intelligence company Xsolis suffered a data breach. The incident affected at least nine healthcare systems and 1.4 million patients. Xsolis issued a notification about the data security incident, and lawyers began an investigation.
Related reports: 5 · last report →
Also affected: 1- Rochester Regional HealthRochester Regional Health notifies 18,600 patients of data leakData leak notification sent to 18,600 patients
Klue hack leaks Salesforce customer data from numerous companies
Impact: Customer data and other information of 200 companies
After Klue was hacked, Salesforce customer relationship management data from multiple companies was leaked through stolen OAuth tokens. Several cyber security companies, including Huntress, confirmed they had been affected, and the number of affected companies was reported at 200. Klue said the criminals were deleting the stolen customer data, but threats from other hackers continued.
Related reports: 10 · last report →
Key incidents in other countries
Data of more than 3 million Texas hunting and fishing licence customers leaked
3mImpact: Personal information of more than 3 million hunting and fishing licence customers
Personal information of more than 3 million hunting and fishing licence customers of the Texas Parks and Wildlife Department was leaked. The potentially exposed information included driving licence details. The Texas Cyber Command detected the breach, and the department warned customers about the impact.
Related reports: 13 · last report →iRhythm Technologies hack leaks patient information
Impact: Patient information
iRhythm Technologies disclosed that hackers had stolen patient information. A June 2024 cyber security incident was cited in connection with the exposure of patient information in its cardiac monitoring system.
Related reports: 8 · last report →Labcorp settles with multiple states over 2019 patient data breach
A patient data breach occurred at Labcorp in 2019. In September 2026, settlements with several states over the incident were announced. The settlement amounts were given differently as $2.2 million, $2.3 million and $2.3 billion, and they do not match.
Related reports: 7 · last report →24 billion stolen records with usernames and passwords exposed online
24bnImpact: 24 billion records containing usernames, passwords, personal information and more
Twenty-four billion stolen records containing usernames, passwords and personal information were exposed online. The exposed credentials included information relating to thousands of sensitive networks.
Related reports: 5 · last report →One Medical Seniors patient data breach and leak threat
Impact: Data of a limited number of patients breached; attackers claim to have stolen 8.8TB
One Medical Seniors said a data breach at a third-party supplier had affected a limited number of patients. ShinyHunters claimed to have stolen 8.8TB of One Medical data and threatened to publish it. It also came to light that a legacy system owned by One Medical had been compromised in a cyber-attack.
Related reports: 5 · last report →