Was M. B. Kahn Construction Co. hit by ransomware?

M. B. Kahn Construction Co. was listed by the coinbasecartel ransomware operation (United States), 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 coinbasecartel ransomware group?

coinbasecartel 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 M. B. Kahn Construction Co. breach?

coinbasecartel published data attributed to M. B. Kahn Construction Co.. Darkfield captured the leak post and a screenshot of the listing.

Ransomware victim disclosure

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M. B. Kahn Construction Co.

Claimed by Coinbasecartel · listed 5 hours ago

Today

Age

since listed · data leaked

Status timeline

ListedAug 1, 2026
Data leakeddate unknown

At a glance

Group: Coinbasecartel
Status: Data leaked
Country: United States
Sector: Manufacturing
Listed on leak site: Aug 1, 2026

About the victim

AI dossier — public-source company profile

M. B. Kahn Construction Co. is a general contracting and construction management firm headquartered in Columbia, South Carolina, founded in 1926. The company operates primarily across the southeastern United States, serving commercial, industrial, healthcare, education, and government markets with services including design-build, preconstruction planning, and facility construction.

Industry: General Contracting & Construction Management
Address: Columbia, South Carolina, US
Founded: 1926

Attack summary

Severity: medium — Data has been published ('data_published' status), indicating confirmed exfiltration, but no specific data inventory, proof file count, or sensitive data types are detailed in the available post excerpt. Construction firms typically hold employee records, client information, and project details; scale and sensitivity cannot be fully assessed from the provided information.

The coinbasecartel group claims to have attacked M. B. Kahn Construction Co. and published data. No specific details regarding encryption, exfiltration scope, or data types are provided in the available post excerpt.

medium

Original description

AI-summarised, not from the leak post

M. B. Kahn Construction Co. is a general contracting and construction management firm based in the United States, headquartered in Columbia, South Carolina. Founded in 1926, the company operates primarily across the southeastern United States. It serves sectors including commercial, industrial, healthcare, education, and government markets, delivering services such as design-build, preconstruction planning, and facility construction.

Sources

Leak posthttp://fjg4zi4opkxkvdz7mvwp7h6goe4tcby3hhkrz43pht4j3vakhy75znyd.onion/companies/mbkahn

Source

Indexed 5 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 coinbasecartel

CoinbaseCartel is a ransomware group that emerged in September 2025 with financially motivated operations targeting organizations across multiple sectors and geographic regions. The group has demonstrated significant activity in a short timeframe, compromising at least 102 known victims primarily across the United States, United Arab Emirates, Germany, Canada, and Brazil. Their targeting patterns show a preference for technology companies, financial services organizations, manufacturing entities, and consumer services businesses, suggesting an opportunistic approach focused on organizations likely to have both valuable data and the financial resources to pay ransoms. Given the group's recent emergence and limited public documentation from established threat intelligence sources, details regarding their specific attack methodologies, infrastructure, and organizational structure remain largely unconfirmed by major cybersecurity firms or law enforcement agencies. The group appears to maintain active operations as of late 2025, though comprehensive analysis of their tactics, techniques, and procedures awaits further investigation and reporting by established threat intelligence organizations. The group has been linked to 196 public disclosures across our corpus. First observed on a leak site on September 15, 2025; most recent post August 1, 2026. The operation is currently active.

Also tracked as: coinbase cartel.

Timeline of this disclosure

August 1, 2026M. B. Kahn Construction Co. listed by coinbasecartelon the group's public leak site

Other recent disclosures by coinbasecartel

coinbasecartel has been linked to 196 public victims on Darkfield. A sample of the most recent:

See the full coinbasecartel dossier →

Sector and geography

This disclosure adds to ransomware activity in the Manufacturing sector, which has 3,684 disclosures indexed across all operators we track. Geographically, M. B. Kahn Construction Co. is reported in United States, a country with 3,138 ransomware disclosures in our corpus.

If your organisation is affected

A listing by coinbasecartel means M. B. Kahn Construction Co. 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 coinbasecartel'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.