high severity February 27, 2026 · 4 min read Unverified claim — what this is

Sejlstrup Listed by The Gentlemen Ransomware Group

If you are a customer of Sejlstrup, here’s what is being claimed, and what it would mean for you.

sejlstrup.dk ***.com/business-directory/company-profiles.sejlstrup_entreprenørforretning_a-s.f02d652f10fa8eb32e3503df8d0d3eb0.html a major construction and contracting company established in 1991 . The company employs 150 people and reported a gross profit of 101.6 million DKK (approx. 13.6 million EUR) in 2023, with excellent profitability ratings . The business is owned by the holding company SEJLSTRUP HOLDING II ApS .
— from The Gentlemen’s own leak-site posting. This is the group’s claim, quoted verbatim; it is not GalaxyWarden’s reporting and has not been independently verified.

Sejlstrup Listed by The Gentlemen Ransomware Group

On February 27, 2026, Danish construction company Sejlstrup was listed on the leak site of the ransomware group known as thegentlemen. The company, which employs 150 people and reported a gross profit of 101.6 million DKK in 2023, is claimed to have had internal files exfiltrated during a ransomware attack. Public reporting indicates that customer, supplier, and employee records may be among the stolen data, although the exact number of affected individuals remains unknown.

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What Public Reporting Shows

Sejlstrup, established in 1991, operates as a major contracting and construction firm in Denmark. It is owned by the holding company SEJLSTRUP HOLDING II ApS. The breach occurred when thegentlemen ransomware operators gained access to the company’s systems, exfiltrated internal files, and later published a sample on their dark web leak site.

Available reporting describes the exposed material as internal documents rather than a simple database dump. No precise inventory of the files has been made public, but construction companies of this size routinely hold names, addresses, national identification numbers, contract details, financial records, and employee payroll information. The listing appeared on February 27, 2026 via an onion address hosted on the ransomware.live aggregator.

Why This Matters for You and Your Family

When a company like Sejlstrup is breached, the people whose information sits in its files are placed at immediate risk. If you or any member of your family has worked with them as an employee, subcontractor, supplier, or customer, your personal data may now be in the hands of criminals. Names, addresses, phone numbers, and financial details can be combined with information from other breaches to build a complete picture of your life.

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What the free scan actually returns

Sample resultyou@email.comIllustrative — not a real person

Found on people-search siteswe remove these

These listings are live, public, and legal to remove — and removing them is what we do.

value redacted in this sampleage, relatives, address historySpokeo

value redacted in this samplephone, household, property recordsBeenVerified

value redacted in this sample580 companies checked

Found in breach recordsverifiedreported — unverified

Each record is labeled: confirmed breach data, or an attacker’s claim no one has verified.

verifiedvalue redacted in this samplepassword + phone · 2024telecom breach

unverifiedvalue redacted in this sampleclaimed in ransomware listing · 2026leak-site claim

Leaked data cannot be deleted from the internet — anyone claiming otherwise is lying. Broker listings can be removed. We do the second, and show you exactly what to fix from the first.

Report details & sourcing

Attributed to The Gentlemen · 1013 incidents tracked →

Severity High the filing does not enumerate what was exposed

Disclosed February 27, 2026

Last reviewed August 8, 2026

Affected Unconfirmed

By GalaxyWarden Threat Research · Editorial & sourcing standards

Unverified claim — what this report is

This page documents a public listing on a ransomware/extortion group’s leak site, tracked via public threat-intelligence sources. A listing is the attacker’s claim. GalaxyWarden aggregates and reports such claims; we have not independently verified that a breach occurred, what data (if any) was taken, or the accuracy of anything the group asserts, and the named organisation has not necessarily confirmed the incident. Sections above describe what the listing shows and the group’s documented history — not verified findings about the named organisation. If you represent this organisation and believe anything here is inaccurate, tell us and we’ll review it promptly.

Editorial & sourcing policy

GalaxyWarden is a breach-monitoring service and news aggregator. We do not exfiltrate, host, purchase, or redistribute stolen data. Breach information is compiled from publicly accessible sources and threat-intelligence platforms, and is reported as claims attributed to their source. We promptly correct or remove material shown to be inaccurate — see our content & takedown policy or write to support@galaxywarden.com.

Threat-actor tracker

The Gentlemen — 1013 incidents tracked

Every breach we've attributed to The Gentlemen, in one running log. See who else they've hit →

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