St Stephen's International listed on thegentlemen ransomware leak site

• Ransomware group: thegentlemen
• Country: Thailand
• Sector: Education
• Announcement date: November 4, 2025

St Stephen's International, an educational institution based in Thailand, has been listed on the leak site of the ransomware group known as thegentlemen. The group claims to have compromised the institution's data, marking a potential security incident for the school.

The alleged incident

On November 4, 2025, the ransomware group known as thegentlemen published an announcement on their leak site listing St Stephen's International. According to the group's claim, they have successfully compromised the institution's data. However, the validity of these claims remains unclear at this time.

Technical observations regarding the announcement indicate that the group's leak site was experiencing a technical error during the verification process. A provided screenshot shows that a verification error occurred while attempting to access the site, which may impact the ability to confirm the details of the claim. Ransomware leak sites are frequently used by threat actors as a method of double extortion. In such scenarios, attackers not only encrypt an organization's systems but also steal sensitive data, threatening to publish it online to pressure the victim into paying a ransom.

Data involved in the claim

At this stage, there is no information provided regarding the content of the allegedly compromised data. The listing does not specify the volume of files or the specific types of information that have been targeted. Furthermore, no ransom demand has been made public in the available information.

• No specific data types were named in the listing.

When organizations face such threats, the lack of immediate information regarding the scope of the breach can create significant uncertainty. Common defensive steps for organizations to mitigate such risks include maintaining robust backup strategies, implementing multi-factor authentication, and conducting regular security awareness training for staff and students to prevent initial access via phishing.

About St Stephen's International

St Stephen's International School is an international educational institution with campuses located in Bangkok and Khao Yai, Thailand. The school provides international standard educational programs and is involved in organizing various social activities and camps for its students.

Risk assessment and implications

Public information regarding the thegentlemen group is limited. The claim of data exfiltration may pose secondary risks such as identity theft or targeted phishing attacks for students and staff. Because educational institutions often hold sensitive personal data, they may be negatively affected by such leaks.

Due to the nature of the data held by schools, the institution may face legal obligations under data protection regulations in Thailand. The actual scope of the compromised data and the accuracy of the group's claims remain unverified. In the broader context of cybersecurity, educational sectors are often targeted because they manage vast amounts of personal, financial, and academic information, making them high-value targets for various cybercriminal activities.