Termotasajero Listed by sinobi Ransomware Group: Ransomware Claim — What’s Alleged & What To Do

Ransomware groups continue to target industrial and energy-sector organisations, treating operational data and internal records as leverage in double-extortion schemes. In this environment, listings on criminal leak sites have become a routine way for threat actors to pressure victims and signal activity to peers.

On 8 October 2025, the ransomware group known as sinobi publicly listed Termotasajero, a Colombian power-generation and commercialisation company. The group claims it exfiltrated internal files during a ransomware attack. The number of people affected remains unknown, and further technical details have not been disclosed in public reporting.

Inside the incident

Public information about the incident is limited to the leak-site listing itself. According to that listing, Termotasajero was subjected to a ransomware attack in which internal files were taken. No confirmed date of initial compromise, no statement on whether systems were encrypted, and no independent verification of the volume or precise nature of the data have been released. The number of individuals whose information may have been involved is listed as unknown. As with many such claims, the listing constitutes an assertion by the threat actor rather than a confirmed disclosure by the organisation or by independent investigators.

No ransom demand amount, negotiation timeline, or evidence package has been described in the available record. Organisations facing such claims typically assess whether the material is authentic, whether it contains regulated personal or operational data, and whether notification obligations under local law have been triggered. Those assessments, if they have occurred, have not been made public.

Inside sinobi

Sinobi is a ransomware operation that has appeared in public tracking of leak sites and double-extortion activity. Like many contemporary groups, it is understood to combine encryption of victim systems with the theft of data, then to threaten publication if payment is not made. The group maintains a dedicated leak site on which it posts victim names and, in some cases, sample files or full archives. Its listings are therefore claims of successful intrusion and data theft; they are not independent confirmations.

Public reporting on sinobi has described typical ransomware tactics: initial access often obtained through phishing, exposed remote services, or compromised credentials; lateral movement inside networks; and the use of custom or commodity ransomware payloads. The group has previously listed organisations across multiple sectors and geographies. Nothing in the public record of this particular listing adds unique technical detail about the methods used against Termotasajero beyond the general claim of internal-file exfiltration.

Termotasajero and its sector

Termotasajero SA ESP operates in power generation and electricity commercialisation. Public descriptions of the company emphasise the supply of electricity to clients, attention to operational effectiveness and sustainability, and initiatives around recycling and environmental management. Energy-sector companies of this type typically maintain extensive operational technology and information-technology environments, commercial contracts, employee records, and regulatory filings.

A breach involving such an organisation is consequential for several reasons. Power-generation entities sit within critical infrastructure; disruption or the exposure of operational data can raise concerns about reliability and safety. They also hold commercial and personal information belonging to employees, contractors, and business partners. Even when the precise contents of stolen files remain unconfirmed, the mere claim of exfiltration can affect trust among clients, regulators, and the public, and can impose costs related to investigation, notification, and remediation.

What was likely exposed

The only data type named in the available facts is “internal files” said to have been exfiltrated in a ransomware attack. No further breakdown—such as whether the material included personal data, financial records, engineering documents, or credentials—has been disclosed. Exact contents therefore remain unconfirmed.

Organisations in the power-generation and energy-commercialisation sector commonly hold employee and contractor personal data, payroll and benefits information, commercial contracts and pricing, operational logs, maintenance records, and correspondence with regulators or grid operators. Any of these categories could theoretically appear among “internal files,” but that possibility is not established fact in this case. Until the organisation or independent analysis provides a verified inventory, the scope of exposure should be treated as unknown.

The real-world impact

For individuals whose data may have been among the internal files, the practical risks include identity fraud, targeted phishing, and misuse of any contact or financial details that were present. Because the number of affected people is unknown and the file contents are unconfirmed, it is not possible to quantify how many people face these risks or how severe they are. Employees, contractors, and business contacts of Termotasajero are the most plausible populations of concern.

For the organisation itself, the consequences can include investigative and forensic costs, potential regulatory scrutiny, contractual notifications to partners, and reputational damage arising from the public listing. Operational continuity may also be affected if systems were encrypted or if recovery required extended downtime; those details have not been reported. The listing alone can create pressure to respond quickly, whether or not the threat actor’s claims are fully accurate.

What to do if you're exposed

If you have a past or present relationship with Termotasajero—as an employee, contractor, supplier, or client—treat the possibility of exposure seriously even while details remain limited. Monitor financial accounts and credit reports for unusual activity, enable multi-factor authentication on email and other important accounts, and be alert to phishing messages that reference the company or the energy sector. Change passwords that may have been reused across work and personal systems. If you receive notification from the company, follow the specific guidance it provides.

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. Such checks do not confirm or rule out involvement in this particular incident, but they can surface other exposures that warrant attention. Remain cautious of unsolicited offers of “breach assistance” or recovery services that arrive after a public listing; these are frequently fraudulent.

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