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 57 public disclosures across our corpus. First observed on a leak site on October 23, 2025; most recent post May 21, 2026. The operation is currently active.

Timeline of this disclosure

February 10, 2026PT. Mitra Antar Tangguh listed by tenguon the group's public leak site

Sector and geography

This disclosure adds to ransomware activity in the Not Found sector, which has 4,859 disclosures indexed across all operators we track. Geographically, PT. Mitra Antar Tangguh is reported in ID, a country with 23 ransomware disclosures in our corpus.

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.

Ransomware victim disclosure

← All victims

PT. Mitra Utama Sinergi Tangguh

listed as PT. Mitra Antar Tangguh · Claimed by tengu · listed 3 months ago

Age

since listed · data leaked

Status timeline

Listed
Feb 10, 2026
Data leaked

At a glance

Group: tengu
Status: Data leaked
Country: ID
Sector: Not Found
Listed on leak site: Feb 10, 2026

About the victim

AI dossier — public-source company profile

PT. Mitra Utama Sinergi Tangguh is a limited liability company (Perseroan Terbatas) officially registered in Indonesia. Beyond its legal structure and Indonesian registration, no further details about its specific business activities, sector, or scale are publicly available from the leak post or a public website.

Industry: Corporate Services / Limited Liability Company (Indonesia)

Attack summary

Severity: medium — Data has been marked as published (disclosed), indicating exfiltration has occurred, but no specific data categories, volumes, or sensitive regulated data types are enumerated, and no operational disruption details are provided.

The Tengu ransomware group (operating under the Shisa RaaS platform) has published data related to PT. Mitra Antar Tangguh, indicating the disclosure status is 'data_published', suggesting exfiltration and/or encryption of company data, though specific volumes or data categories are not enumerated in the post.

medium

Data the group says was taken

AI dossier — extracted from the leak post

Company registration documents
Internal business data

What the group claims

PT. Mitra Utama Sinergi Tangguh is 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

Shisa Ransomware Blog Shisa RANSOMWARE DATA LEAKS BLOG HOME AFFILIATE PROGRAM CONTACT crown-security.com.tw PUBLISHED 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 27,470 👁 Sileno Companies Inc PUBLISHED 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 29,787 👁 Eos Technology srl PUBLISHED 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, h…

Sources

Leak posthttp://longcc4fqrfcqt5lzceutylaxir6h66fp6df3oin6mvwvz6pfdbxc6qd.onion/blog/8e727d2c25e6977f456254dcd8be14b8586951d2816d3ef3d8afb06b1de3f3ad/

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.