PT Kalimantan Prima Persada Listed by medusa Ransomware Group: Ransomware Claim — What’s Alleged & What To Do

PT Kalimantan Prima Persada, an Indonesian coal-mining subsidiary of PT Pamapersada Nusantara, has been listed by the medusa ransomware group as of a report dated 6 November 2025. Public information states that internal files were exfiltrated in a ransomware attack; the number of people affected remains unknown and further technical details have not been released.

The listing itself is a claim by the group. No independent confirmation of the full scope, method or exact contents has been published, so the picture available to the public is limited to what the organisation’s ownership structure and the ransomware claim currently indicate.

Inside the incident

According to the available record, PT Kalimantan Prima Persada was named on medusa’s leak site on or around 6 November 2025. The sole concrete description supplied is that internal files were allegedly exfiltrated during a ransomware attack. No figure for the volume of data, no list of specific file categories, no timeline of intrusion or encryption, and no statement on whether systems remain offline have been disclosed. The number of individuals whose information may have been involved is recorded as unknown. Beyond the group’s listing and the brief characterisation of the data as “internal files,” public detail on the incident is limited.

Who is medusa?

Medusa is a ransomware operation that has been active for several years and is documented as using a double-extortion model: encrypting systems while also copying data and threatening to publish it if a ransom is not paid. The group maintains a public leak site on which it posts victim names and, in some cases, sample files. It typically operates as a ransomware-as-a-service platform, allowing affiliates to deploy its tools. Prior public activity has included listings of organisations across manufacturing, logistics, professional services and other sectors. In the present case the group claims to have obtained internal files from PT Kalimantan Prima Persada; that claim has not been independently verified in the material available.

PT Kalimantan Prima Persada and its sector

PT Kalimantan Prima Persada (KPP) is a subsidiary of PT Pamapersada Nusantara (PAMA), itself a major mining contractor in Asia. Ownership is reported as 99.99 percent held by PAMA and 0.01 percent by PT United Tractors Pandu Engineering. Established to expand services across the coal-mining value chain—from exploration through sales—KPP has operated since 2003 as part of PAMA’s next-generation mining-developer concept, focusing on small- and medium-scale coal operations in Kalimantan. Companies of this type routinely manage geological surveys, production schedules, contractor and employee records, commercial contracts, and operational logistics data. A ransomware incident affecting such an organisation therefore touches both industrial operations and the personal or commercial information those operations generate.

What data was at risk

The only description given is that internal files were allegedly exfiltrated. No inventory of the precise data types—whether employee personal details, contractor agreements, geological reports, financial records or other categories—has been published. Organisations engaged in coal mining and related services typically hold personnel files, operational plans, supplier and customer information, and technical documentation. Because the exact contents remain unconfirmed, it is not possible to state with certainty which of these categories, if any, were included in the claimed exfiltration.

Why it matters

For individuals whose information may have been among the internal files, the practical risks include potential misuse of personal identifiers, contact details or employment-related data for phishing, identity fraud or social engineering. For the organisation, the consequences can include operational disruption, contractual liabilities toward partners and clients, regulatory scrutiny under Indonesian data-protection rules, and reputational effects that affect ongoing mining contracts. Because the scale of the exfiltration and the number of people affected are unknown, the precise extent of these risks cannot yet be quantified; the absence of confirmed detail itself prolongs uncertainty for anyone connected to the company.

If your data was in this claimed breach

If you have reason to believe your information may have been held by PT Kalimantan Prima Persada or its parent entities, the following steps are prudent:

• Monitor financial and email accounts for unexpected activity and enable multi-factor authentication where available.
• Treat unsolicited messages that reference mining contracts, employment or payments with caution; verify any request through known official channels.
• Consider placing fraud alerts with relevant credit or identity-protection services if personal identifiers were likely stored.
• Retain records of any correspondence you receive that appears linked to the incident.

Readers can also run a free exposure scan of their email address to check whether that address has already appeared in known breach data sets. Public information on this particular incident remains limited; further official statements from the company or regulators would be required to clarify the full scope.

AICompiled with AI assistance from public sources and published under our editorial standards.