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

M.B. Kahn Construction Co. was listed by the coinbasecartel ransomware operation (United States) as a victim being extorted; data had not been published at the time of listing. 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.

Ransomware victim disclosure

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M.B. Kahn Construction Co.

Claimed by Coinbasecartel · listed 3 days ago

Age

since listed · listed for ransom

Status timeline

ListedAug 15, 2026

Current state: Listed for ransom

At a glance

Group: Coinbasecartel
Status: Listed for ransom
Country: United States
Sector: Construction
Listed on leak site: Aug 15, 2026

About the victim

AI dossier — public-source company profile

M.B. Kahn Construction Co. is a construction company operating in the United States. No further details are available from public sources.

Industry: Construction

Attack summary

Severity: medium — Company listed with data samples posted on leak site, but no specific data types, volume, or operational impact details provided in the post.

The coinbasecartel group claims to have exfiltrated data from M.B. Kahn Construction Co. and posted data samples to their leak site. The group states they attempted contact before disclosure.

medium

The leak post

captured from the group's site

Caterpillar CEN & CENELEC CM-Telematics Colliers Real Estate M.B. Kahn Siveco Data samples have been posted on the below link http:qms2rnbz62y3edl4ohhihg6ycqonpliibatkkcer5mokixwnqlwqalqd.onion
— We are looking for new partners/insiders. Send us a message to dicuss
We tried to reach out to you to solve this, contact us fast before this gets out of control.
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Caterpillar CEN & CENELEC CM-Telematics Colliers Real Estate M.B. Kahn Siveco Data samples have been posted on the below link http:qms2rnbz62y3edl4ohhihg6ycqonpliibatkkcer5mokixwnqlwqalqd.onion

Screenshot of the leak post

Leak screenshot for M.B. Kahn Construction Co.

Sources

Leak posthttp://fjg4zi4opkxkvdz7mvwp7h6goe4tcby3hhkrz43pht4j3vakhy75znyd.onion

Source

Indexed 3 days 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 203 public disclosures across our corpus. First observed on a leak site on September 15, 2025; most recent post August 15, 2026. The operation is currently active.

Also tracked as: coinbase cartel.

Timeline of this disclosure

August 15, 2026M.B. Kahn Construction Co. listed by coinbasecartelon the group's public leak site

Other recent disclosures by coinbasecartel

coinbasecartel has been linked to 203 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 Construction sector, which has 988 disclosures indexed across all operators we track. Geographically, M.B. Kahn Construction Co. is reported in United States, a country with 3,162 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 is being pressured to pay before any publication. 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.