Sincere Corporation Listed by thegentlemen Ransomware Group

On January 20, 2026, Japanese environmental services company Sincere Corporation appeared on the leak site operated by the ransomware group known as thegentlemen. The listing indicates that internal files were exfiltrated during a ransomware attack on the company, which operates under the name Sincerehq.com and provides waste management, recycling, building maintenance, and environmental consulting services across Japan.

What Public Reporting Shows

Public reporting indicates that Sincere Corporation, founded in 1969 and based in Japan, was listed by thegentlemen ransomware operators. The company maintains major facilities in Shinagawa and Yokohama and describes its business philosophy as “Symbiosis with Nature.” Available reporting describes the incident as a ransomware attack in which internal files were taken. The exact number of people whose information may have been exposed remains unknown, and the specific types of data contained in the exfiltrated files have not been publicly detailed. The primary source for the listing is the group’s leak site, accessible via the onion address hosted on ransomware.live.

Why This Matters for You and Your Family

When a company like Sincere Corporation suffers a breach, the information stolen can include documents that contain names, addresses, contact details, or other personal records of customers, partners, or employees. If your family has used their waste management, recycling, or environmental consulting services, your information could be among the files now in attackers’ hands. Credential leaks from such incidents often cascade into account takeovers on other sites where the same email and password are reused. For families, this risk extends to children’s accounts, especially gaming platforms that frequently rely on shared family email addresses or phone numbers. Once initial data appears, it can be combined with other breaches to build a detailed profile that puts your household at risk of identity theft, phishing, or harassment.

The Doxxing and Identity-Chain Implications

Ransomware groups rarely limit themselves to one dataset. Exfiltrated internal files can contain spreadsheets, contracts, employee directories, or customer databases that link names to addresses, phone numbers, email accounts, and sometimes dates of birth. These fragments allow attackers or data resellers to map connections between your online handles, work history, family members, and real-world identity. What begins as a corporate breach can quickly fuel doxxing chains, where one exposed record leads to others on forums, paste sites, or dark-web marketplaces. Gaming accounts belonging to you or your children are particularly vulnerable because they often share the same email addresses or recovery phone numbers used for adult services, creating a single point of failure that can expose the entire household.

Thegentlemen Ransomware Group’s Track Record

Public reporting attributes the attack to the ransomware group known as thegentlemen. The group emerged in recent years and has targeted organizations across multiple sectors by gaining initial access, exfiltrating data, and then publishing samples on their leak site when victims do not meet extortion demands. Their typical playbook involves ransomware deployment followed by threats to release stolen files unless a ransom is paid. Notable prior victims have included companies in various industries, though specific details beyond the current Sincere Corporation listing remain limited in available public reporting. Readers can follow trackers dedicated to thegentlemen for updates on their activity.

What to do

• Run a DoxxScan to map every link between your emails, phone numbers, handles, and real identity so you can see exactly what chains back to the Sincere Corporation breach.
• Enable continuous DoxxScan monitoring across 13.1B+ breach records and 100+ platforms so the next leak exposing your family is caught in hours rather than months.
• Rotate any password you used at Sincerehq.com or related services anywhere it has been reused, and switch to 2FA through an authenticator app instead of SMS.
• Cover the household with DoxxScan family protection that extends to dependents and children’s gaming accounts, which often chain back to the same addresses or recovery details exposed in incidents like this.
• Let remediation specialists handle takedown requests for any exposed personal records across data brokers and leak sites on your behalf.

The Sincere Corporation breach is a reminder that corporate ransomware incidents now routinely feed into larger identity-exposure ecosystems that can affect ordinary families months or years later. Taking concrete steps now limits how far attackers can travel down the chain of information connected to your household. DoxxScan by GalaxyWarden delivers continuous monitoring across 13.1 billion+ breach records and more than 100 platforms, AI-powered identity-chain mapping, and hands-on remediation by specialists, including coverage for your family and children’s gaming accounts that are frequently targeted once credential leaks begin to cascade.