Was Cosmo Group hit by ransomware?

Cosmo Group was listed by the thegentlemen ransomware operation (Thailand), and stolen data was published on the group's leak site. Darkfield tracks this disclosure with the original leak post, screenshot and group context.

Who is the thegentlemen ransomware group?

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

What data was leaked in the Cosmo Group breach?

thegentlemen published data attributed to Cosmo Group. Darkfield captured the leak post and a screenshot of the listing.

Ransomware victim disclosure

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Cosmo Group PCL

listed as Cosmo Group · Claimed by Thegentlemen · listed 2 months ago

54d

Age

since listed · data leaked

Status timeline

ListedApr 19, 2026
Data leakeddate unknown

At a glance

Group: Thegentlemen
Status: Data leaked
Country: Thailand
Listed on leak site: Apr 19, 2026

About the victim

AI dossier — public-source company profile

Cosmo Group PCL is a Thai luxury packaging manufacturer headquartered in Bangkok (Sukhumvit), founded in 1964 with over 60 years of experience. The company specialises in premium gift boxes, displays, watch dials, cases, and accessories for global luxury brands in the jewelry, watches, cosmetics, and perfume sectors. It operates internationally, including a Swiss sales office (Cosmo Pusterla 1880), and holds multiple quality and sustainability certifications.

Industry: Luxury Packaging Manufacturing
Address: Sukhumvit, Bangkok, Thailand
Employees: 1000-5000
Founded: 1964

Attack summary

Severity: high — Data has been confirmed as published (data_published status) indicating successful exfiltration from a large company (1,000–5,000 employees) serving top-tier international luxury brand clients, likely containing significant business-sensitive and client data.

The group 'thegentlemen' claims to have attacked Cosmo Group PCL with data now published (disclosed status: data_published), indicating exfiltration of company data. No specific ransom amount or data volume was stated in the post.

high

Data the group says was taken

AI dossier — extracted from the leak post

Company business data
Client information (luxury brand partners)
Internal corporate records

What the group claims

cosmo.co.th zoominfo.com/c/cosmo-group-public-co/459326707 Cosmo Group PCL, founded in 1964 and headquartered in Bangkok (Sukhumvit), is a Thai luxury packaging manufacturer with over 60 years of experience. The company specializes in premium gift boxes, displays, watch dials, cases, and accessories for global luxury brands in jewelry, watches, cosmetics, and perfume. With 1,000–5,000 employees and a Swiss sales office (Cosmo Pusterla 1880), Cosmo serves top-tier international clients and holds multiple quality and sustainability certifications

Sources

Victim sitecosmo.co.th

Source

Indexed 2 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 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 483 public disclosures across our corpus. First observed on a leak site on September 9, 2025; most recent post June 11, 2026. The operation is currently active.

Also tracked as: the gentlemen.

Timeline of this disclosure

April 19, 2026Cosmo Group listed by thegentlemenon the group's public leak site

Other recent disclosures by thegentlemen

thegentlemen has been linked to 483 public victims on Darkfield. A sample of the most recent:

See the full thegentlemen dossier →

Sector and geography

Geographically, Cosmo Group is reported in Thailand, a country with 45 ransomware disclosures in our corpus.

If your organisation is affected

A listing by thegentlemen means Cosmo Group 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.