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Thompson Builders Corporation

Claimed by Securotrop · listed 2 months ago

2m
Age
since listed · data leaked

Status timeline

  1. ListedMay 4, 2026
  2. Data leakeddate unknown

At a glance

Group
Securotrop
Status
Data leaked
Country
United States
Sector
Construction
Listed on leak site
May 4, 2026

About the victim

AI dossier — public-source company profile

Thompson Builders Corporation (TBC) is a Bay Area-based general contractor serving California since 1989. The company specializes in design/build, lease-leaseback, general contracting, pre-construction, and value engineering services for public and private sector clients. It has completed over 200 large-scale commercial and civil projects with a cumulative contract value exceeding $2 billion.

Industry
Commercial & Civil General Contracting
Address
Bay Area, California, US
Founded
1989

Attack summary

Severity: high — 3,633 GB of confirmed exfiltrated data from a major general contractor with public-sector clients represents a significant volume of potentially sensitive business, financial, and project data; public agency client data may include regulated records, warranting a high severity rating.

The group 'securotrop' claims to have exfiltrated approximately 3,633 GB of data from Thompson Builders Corporation, with the post status listed as 'AWAITING', suggesting data has been published or is staged for release pending a response. No ransom amount was stated.

high

Data the group says was taken

AI dossier — extracted from the leak post
  • Project documents and contracts
  • Financial records
  • Subcontractor and supplier information
  • Employee records
  • Client/public agency data
  • Design and engineering files

What the group claims

Status: AWAITING Size: 3633 GB

Sources

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 securotrop

Securotrop is a relatively new ransomware group that emerged in July 2025 and operates with apparent financial motivations, having targeted at least 31 victims across multiple sectors. The group primarily targets English-speaking countries including the United States, Canada, and the United Kingdom, with their attacks focused heavily on manufacturing companies, business services firms, construction organizations, and telecommunications providers. Due to the group's recent emergence and limited public documentation from major cybersecurity agencies and researchers, specific details about their country of origin, operational structure, attack methodologies, and technical capabilities remain largely undocumented in open-source intelligence reports. The targeting pattern suggests a focus on critical infrastructure and industrial sectors that may be willing to pay ransoms to quickly restore operations, though no major high-profile attacks or record ransom demands have been publicly reported by established threat intelligence sources. Given the group's recent formation in mid-2025, Securotrop appears to remain active, though comprehensive analysis of their tactics, techniques, and procedures awaits further documentation by cybersecurity researchers and law enforcement agencies. The group has been linked to 38 public disclosures across our corpus. First observed on a leak site on July 22, 2025; most recent post July 15, 2026. The operation is currently active.

Timeline of this disclosure

  • May 4, 2026Thompson Builders Corporation listed by securotropon the group's public leak site

Other recent disclosures by securotrop

securotrop has been linked to 38 public victims on Darkfield. A sample of the most recent:

See the full securotrop 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, Thompson Builders Corporation is reported in United States, a country with 3,115 ransomware disclosures in our corpus.

If your organisation is affected

A listing by securotrop means Thompson Builders Corporation 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.
  • Report the incident to your national CERT, CISA (United States), as required for your jurisdiction.
  • Monitor for the data appearing on securotrop'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.