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Mahajak Development Co., Ltd.

listed as Mahajak Development · Claimed by Thegentlemen · listed 7 hours ago

Today
Age
since listed · data leaked

Status timeline

  1. ListedJun 15, 2026
  2. Data leakeddate unknown

At a glance

Group
Thegentlemen
Status
Data leaked
Country
Thailand
Sector
Construction
Listed on leak site
Jun 15, 2026

About the victim

AI dossier — public-source company profile

Mahajak Development Co., Ltd. is a Thai technology provider established in 1971 and headquartered in Bangkok. Originally an automotive air-conditioning distributor, the company now specializes in supplying Mitsubishi Heavy Duty climate systems, smart home automation, and professional audio-visual solutions, with comprehensive consulting, design, and installation services for commercial and government projects across Thailand.

Industry
HVAC Systems, Smart Home Automation & Professional Audio-Visual Solutions
Address
Bangkok, Thailand
Founded
1971

Attack summary

Severity: low — Listing/announcement only with no proof files, screenshots, or specific data inventory published. No operational disruption or confirmed data exfiltration details provided.

The ransomware group 'thegentlemen' claims to have compromised Mahajak Development. The specific nature of the attack (encryption, exfiltration, or both) and the data categories at risk are not detailed in the available leak post.

low

What the group claims

***.com zoominfo.com/c/mahajak-development-co-ltd/346627274 Mahajak Development Co., Ltd. is a leading Thai technology provider established in 1971, headquartered in Bangkok. Evolving from an automotive air-conditioning distributor, they are now a premier supplier of Mitsubishi Heavy Duty climate systems, smart home automation, and professional audio-visual solutions. The company delivers comprehensive consulting, design, and installation services for commercial projects and government facilities across Thailand

Sources

Source

Indexed 7 hours 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 thegentlemen

thegentlemen is a ransomware group that emerged in September 2025, operating with apparent financial motivations based on their broad targeting of commercial sectors. The group has documented 267 victims across multiple countries, with primary focus on the United States, Thailand, France, Brazil, and India. Their targeting strategy demonstrates a preference for high-value sectors including manufacturing, technology, healthcare, and financial services organizations. Given the group's recent emergence and limited public documentation from established threat intelligence sources such as CISA, FBI, or major security research firms, specific details regarding their country of origin, operational structure, attack methodologies, encryption techniques, and whether they employ ransomware-as-a-service models remain unclear. The relatively high victim count of 267 in a short operational timeframe since September 2025 suggests either an aggressive campaign pace or potential inflation of victim numbers through affiliate operations, though without corroborating intelligence reports, the group's exact operational capabilities and notable campaigns cannot be definitively established. Current intelligence indicates the group remains active as of late 2025, though comprehensive threat profiling requires additional validated reporting from authoritative cybersecurity sources. The group has been linked to 504 public disclosures across our corpus. First observed on a leak site on September 9, 2025; most recent post June 15, 2026. The operation is currently active.

Also tracked as: the gentlemen.

Timeline of this disclosure

  • June 15, 2026Mahajak Development listed by thegentlemenon the group's public leak site

Other recent disclosures by thegentlemen

thegentlemen has been linked to 504 public victims on Darkfield. A sample of the most recent:

See the full thegentlemen dossier →

Sector and geography

This disclosure adds to ransomware activity in the Construction sector, which has 988 disclosures indexed across all operators we track. Geographically, Mahajak Development is reported in Thailand, a country with 59 ransomware disclosures in our corpus.

If your organisation is affected

A listing by thegentlemen means Mahajak Development appeared on a ransomware extortion site and data attributed to it has been published. 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 thegentlemen'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.