Centrum.sk listed on apt73 leak site

• Ransomware group: apt73
• Country: Slovakia
• Sector: Technology
• Announcement date: April 27, 2026

The threat actor group apt73 claims a breach of centrum.sk

The Slovakian-based online portal centrum.sk has been listed on a leak site belonging to the threat actor group known as apt73. According to the announcement made on April 27, 2026, the group claims to have successfully executed an attack against the organization on the same day. The listing indicates a significant data breach, with the threat actors claiming to have obtained approximately 60 GB of data from the target.

The announcement follows a pattern often seen in modern cyberattacks where threat actors use leak sites to publicize their successes. In this instance, the group has provided samples of the alleged exfiltrated data in the form of images showing official-looking documents to support their claims. This method is frequently used by cybercriminals to demonstrate the validity of their theft and to increase the pressure on the victim organization.

Details of the alleged data exfiltration

The claims made by apt73 suggest that the breach has compromised a wide variety of sensitive information. The group alleges that the stolen data includes not only internal corporate documentation but also communications and personal details. The scope of the alleged theft is substantial, involving a large volume of files that could impact various levels of the organization's operations.

According to the group's claims, the leaked data includes the following types of information:

• Internal documents
• Emails
• Contact lists
• Financial documents
• Personal information

The presence of such diverse data types, ranging from financial records to personal information and emails with attachments, suggests a deep level of access within the organization's network. While the specific number of files has not been disclosed, the claimed volume of 60 GB highlights the potential scale of the incident.

About centrum.sk

Centrum.sk is a popular internet portal based in Slovakia. It serves a significant user base by providing various online content, news, and essential email services. Because the organization acts as a provider of email services, the potential impact of a data leak involving email communications and contact lists could be significant for the individuals relying on their platform.

Analysis and potential implications

This incident highlights the use of double-extortion tactics by threat actors. In a double-extortion scenario, attackers do not merely encrypt a victim's systems; they also steal sensitive data and threaten to publish it on public leak sites to exert maximum pressure on the organization. This tactic is designed to force a ransom payment by leveraging the threat of reputational damage and legal consequences.

For an organization like centrum.sk, which is based in Slovakia, such a leak may lead to legal consequences under the European Union's General Data Protection Regulation (GDPR). The breach of personal information and contact lists poses secondary risks to both the organization's employees and its users, including the potential for identity theft and highly targeted phishing attacks. When attackers possess emails and contact lists, they can craft much more convincing social engineering campaigns.

While information regarding the apt73 group remains limited, the incident underscores the ongoing risks faced by technology and service-oriented sectors. Organizations in this sector often implement defensive measures such as multi-factor authentication, robust encryption for data at rest and in transit, and continuous monitoring to detect unauthorized exfiltration. However, as seen in this claim, the threat of large-scale data theft remains a primary concern for digital service providers globally.