Was PT. Mitra Utama Sinergi Tangguh hit by ransomware?

PT. Mitra Utama Sinergi Tangguh was listed by the tengu ransomware operation (Indonesia) as a victim being extorted; data had not been published at the time of listing. Darkfield tracks this disclosure with the original leak post, screenshot and group context.

Who is the tengu ransomware group?

tengu is a ransomware operator tracked by Darkfield. See the full operator dossier for its known victims, sectors targeted, IOCs and leak-site infrastructure.

Ransomware victim disclosure

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PT. Mitra Utama Sinergi Tangguh

Claimed by Tengu · listed 3 months ago

22.9 TB

Data size

Age

since listed · listed for ransom

Status timeline

ListedMay 27, 2026

Current state: Listed for ransom

At a glance

Group: Tengu
Status: Listed for ransom
Country: Indonesia
Sector: Business Services
Listed on leak site: May 27, 2026
Data size: 22.9 TB

About the victim

AI dossier — public-source company profile

PT. Mitra Utama Sinergi Tangguh is an Indonesian business services company. Limited public information is available about the company's specific operations or scale.

Industry: Business Services

Attack summary

Severity: low — The post lists the victim name but provides no verifiable proof, no data exfiltration confirmation specific to PT. Mitra Utama Sinergi Tangguh, and no clear operational impact. The leak post content appears to be boilerplate descriptions of unrelated companies, which suggests either a low-effort listing or a collection error by the threat actor.

The Tengu group claims to have attacked PT. Mitra Utama Sinergi Tangguh. However, the leak post provided contains descriptions of multiple unrelated companies (Crown Security, Sileno Companies, Eos Technology, Community Mosaic, DaintyCloud, Martec Marine, Al Arif Contracting, Shora Advisory, Femar Group) with no clear evidence that any of these are the actual victim or that PT. Mitra Utama Sinergi Tangguh was compromised.

low

What the group claims

A company officially registered in Indonesia in the form of a limited liability company (PT – Perseroan Terbatas).

The leak post

captured from the group's site

Crown Security is a technology company specializing in information security and digital systems, offering advanced solutions to protect corporate networks and data from breaches and cyberattacks The company focuses on providing security consulting and implementing integrated protection systems tailored to each organization's needs 
Sileno Companies Inc. A US company primarily operating in the hospitality and real estate sectors, its activities include: Hotel operation Property management Management of hotels' restaurants and bars Hospitality project development 22.9TB was encrypted in 14 hours on 3/5/2026 More than 67.07 GB was extracted 
Eos Technology srl is a company with 15 years of experience in the ICT sector, initially starting as an assembly and repair laboratory for PCs and peripherals. Over time, it has developed expertise that has allowed it to become a partner of various international brands. The company offers a range of services including IT assistance, multimedia services, help desk support, corporate security systems, and the design of virtual switchboards and video surveillance systems. Eos Technology srl aims to provide consulting services to clients navigating th…

Screenshot of the leak post

Leak screenshot for PT. Mitra Utama Sinergi Tangguh

Sources

Leak posthttp://longcc4fqrfcqt5lzceutylaxir6h66fp6df3oin6mvwvz6pfdbxc6qd.onion

Source

Indexed 3 months ago

This page surfaces a public ransomware disclosure indexed by Darkfield. Original posts come from the operator's own leak site; we cross-check against ransomware.live, RansomLook and RansomWatch where applicable. Share this URL freely.

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Disclosure context

About tengu

Tengu is a recently emerged ransomware group first observed in October 2025, operating with apparent financial motivations and demonstrating a geographically diverse targeting approach across 49 documented victims. The group has primarily focused their operations on Morocco, the United States, India, Italy, and Indonesia, suggesting either opportunistic targeting or specific interest in these regions' economic sectors. Their victim profile spans multiple industries including technology, manufacturing, public sector, and agriculture and food production, indicating a broad targeting strategy rather than sector-specific focus. Due to the group's recent emergence and limited public documentation from established threat intelligence sources, specific details regarding their origin, affiliation status, technical methodology, encryption techniques, and operational structure remain largely undocumented by major cybersecurity agencies and research organizations. No notable high-profile campaigns or law enforcement actions have been publicly reported by CISA, FBI, or prominent security researchers at this time. The group's current operational status appears active given their recent emergence, though comprehensive threat intelligence profiles from established sources have yet to be published due to their nascent presence in the ransomware landscape. The group has been linked to 59 public disclosures across our corpus. First observed on a leak site on October 23, 2025; most recent post May 28, 2026. The operation is currently active.

Timeline of this disclosure

May 27, 2026PT. Mitra Utama Sinergi Tangguh listed by tenguon the group's public leak site

Data size: 22.9 TB

Other recent disclosures by tengu

tengu has been linked to 59 public victims on Darkfield. A sample of the most recent:

See the full tengu dossier →

Sector and geography

This disclosure adds to ransomware activity in the Business Services sector, which has 3,796 disclosures indexed across all operators we track. Geographically, PT. Mitra Utama Sinergi Tangguh is reported in Indonesia, a country with 77 ransomware disclosures in our corpus.

If your organisation is affected

A listing by tengu means PT. Mitra Utama Sinergi Tangguh appeared on a ransomware extortion site and is being pressured to pay before any publication. If this is your organisation, or a supplier you depend on, the priority is to confirm the intrusion and contain it before the window to act closes.

Engage your incident-response team and preserve forensic evidence before remediating — do not wipe affected systems first.
Force a password reset and revoke active sessions for exposed accounts; rotate any credentials, API keys or certificates that may have been in the stolen data.
Assess regulatory notification duties (GDPR, NIS2, sector regulators) — many carry a 72-hour reporting clock from awareness.
Monitor for the data appearing on tengu's leak site and across paste and breach channels, and brief downstream partners who may be exposed through you.

How we know this. Darkfield monitors public ransomware leak sites continuously, archiving every new disclosure and the data later released against the victim. Each entry on this page is sourced from the operator's own publication and cross-checked against complementary OSINT feeds (RansomLook, ransomware.live, RansomWatch). We do not collect or host stolen data — only the metadata, timestamps and screenshots needed to make the public disclosure searchable and accountable. Records here are corrected when the original post is edited, retracted, or merged with another disclosure.