Week 44, 2023 security incident report
Hacking and data breach incidents newly reported 2023.10.30 ~ 11.05
In South Korea, the leak of members' personal data following the hacking of the Dong Hang Lottery website drew the most attention, with 14 articles, and the leaks of resumes belonging to 230,000 Worknet members and of personal data of 130,000 Samjjeomsam users also came to light. Personal data damage stood out, including the arrest of a hacking ring that stole 8.5 million personal records and traded them on social media, and related incidents followed in a range of fields including education, employment, tax and academia. Further damage from the abuse of compromised systems also emerged, as an intrusion into STO's customer text-messaging system led to smishing messages being sent to all of its customers, and the detection of a voice phishing operation worth 150 billion won was also reported. Overseas, ransomware attacks on the British Library, Toronto Public Library, Boeing and hospitals in Ontario, Canada, resulted in both data theft and disruptions to services and patient care.
By type
- Data breach16
- Hacking & intrusion15
- Ransomware7
- Phishing & smishing3
- Malware1
Key incidents in South Korea
Donghaeng Lottery website hack exposes member personal data
Impact: Members' personal information including names and phone numbers
In November 2023, the Donghaeng Lottery website was hit by an external hacking attack, and the possible leak of members' personal information such as names and phone numbers was confirmed. Donghaeng Lottery temporarily suspended its service and carried out an emergency system inspection, saying passwords for individual IDs were not exposed. A penalty surcharge was later imposed over the personal data leak.
Related reports: 14 · last report →Chunjae Textbook loses appeal in suit to cancel fine over personal data leak
23KImpact: Personal data of more than 23,000 Milk T users
In 2021, the personal data of more than 23,000 users of Chunjae Textbook's Milk T was leaked. Chunjae Textbook filed a lawsuit to cancel the 900 million won fine imposed on it but lost again on appeal. The court found that the Milk T database could be accessed through Chunjae Education's web server and that Chunjae Textbook had failed to fulfill its duty to restrict access rights.
Related reports: 2 →Intrusion into STO's customer messaging system used to send smishing texts
Impact: Smishing texts sent to all customers
An outsider accessed STO's information network and used its customer messaging system to send all customers smishing texts disguised as traffic fine notices. The Korea Internet & Security Agency (KISA) confirmed that the app linked in the texts was a malicious app capable of stealing personal data and remotely controlling smartphones. The company apologized, reported the incident to KISA and requested a police investigation, and no leak of customer information was confirmed.
Related reports: 2 →Hacking ring that stole 8.5 million personal data records and traded them on social media arrested
8.5MImpact: 8.5 million personal data records
A hacking ring that stole 8.5 million personal data records was arrested. The group traded the stolen personal data via social media.
Read on 뉴시스 ↗Worknet hack leaks personal data in résumés of 230,000 members
230KImpact: Personal data in the résumés of 230,000 members
Worknet was hacked, leaking personal data in the résumés of 230,000 members. The unauthorized overseas access and data leak went unnoticed for seven days. Management problems also came to light, including limited working hours for on-site security monitoring staff.
Read on 보안뉴스 ↗Personal data of 130,000 Samjjeomsam users leaked without consent
130KImpact: Personal data of 130,000 people
Claims were made that a leak of personal data of 130,000 people without consent had been confirmed at Samjjeomsam. The specific timing of the leak, the data involved and the response have not been confirmed.
Read on 세무사신문 ↗Korean Society of Food Science and Nutrition leaks names, specialties and other personal data
Impact: Personal data including names and areas of specialization
Personal data including names and areas of specialization was leaked at the Korean Society of Food Science and Nutrition. The specific number of people affected, the timing of the leak, the cause and the response have not been confirmed.
Read on 민주신문 ↗Kakao Games unveils compensation for Odin update information leak
Impact: Leak of Odin update information
Kakao Games unveiled a compensation plan for the leak of Odin update information. The specific timing and circumstances of the leak and the details of the compensation have not been confirmed.
Read on 게임톡 ↗Hackers take over bookstores' and authors' social media accounts, demand 600 euros
Impact: Social media accounts of bookstores and authors hacked
A series of social media accounts belonging to bookstores and authors were hacked. The attackers threatened to delete the accounts unless 600 euros was paid.
Read on 연합뉴스 ↗Voice phishing operation that swindled 150 billion won uncovered
Impact: 150 billion won in financial losses
A voice phishing operation that swindled 150 billion won was uncovered. Evidence emerged that the perpetrators had even practiced deepfakes impersonating prosecutors.
Read on YTN ↗
Key incidents in other countries
Ransomware attack on British Library disrupts services and leaks data
Impact: Leak of staff and user information and internal documents; disruption of online, phone and on-site services
The British Library was hit by a ransomware attack on October 28, 2023, disrupting its website, online catalog, access to digital collections, and phone and on-site services. Staff and user information and internal documents were leaked, and the Rhysida group claimed responsibility for the attack. The National Cyber Security Centre and outside experts joined the investigation, and the library gradually resumed services, including restoring access to its online collections in January 2024.
Related reports: 32 · last report →Toronto Public Library ransomware leads to data theft and service outage
Impact: Theft of file server data including employees' personal information, and disruption of library services
Toronto Public Library was hit by a ransomware attack on October 28, 2023, disrupting online accounts, digital collections, public computers and printing services. A large amount of data was stolen from a file server, and the leak of personal information including employees' Social Insurance Numbers was confirmed. It was also suggested that copies of employees' identification documents since 1998 and some information on patrons, volunteers and donors may have been affected. The library restored services in stages and in December 2024 released the results of its lengthy investigation.
Related reports: 14 · last report →Boeing ransomware attack disrupts services and leaks data
Impact: Disruption of global services and data leak
Boeing was hit by a cyberattack in 2023 that disrupted its global services. LockBit published data it claimed to have stolen from Boeing, and Boeing investigated the leaked data. In May 2024, Boeing confirmed that it had received a $200 million ransom demand at the time and had refused to pay.
Related reports: 11 · last report →Ransomware attack on Ontario hospitals disrupts care and compromises data
5.6MImpact: Theft of information on 5.6 million patient visits and cancellation of cancer treatment appointments
Hospitals in Ontario, Canada, were hit by a ransomware attack that led to canceled cancer treatment appointments and the theft of information covering 5.6 million patient visits. The attackers demanded a ransom of millions of dollars, and the hospitals expected recovery to take weeks. A $480 million class action lawsuit was later filed against the 5 affected hospitals.
Related reports: 7 · last report →LastPass 2022 breach affected 1.6 million UK users
1.6MImpact: Data of 1.6 million UK users leaked
In 2022, LastPass suffered a data breach in which password vaults were stolen, affecting 1.6 million users in the UK. Investigators said crypto thefts believed to be linked to the breach cost more than 25 people about $4.4 million in a single day, October 25, 2023. UK authorities fined LastPass £1.2 million in December 2025.
Related reports: 6 · last report →