high severity December 05, 2023 · 3 min read Unverified claim — what this is

concertus.co.uk Listed by Abyss Ransomware Group

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

Concertus Design and Property Consultants 1,9Tb uncompressed data
— from Abyss’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.

concertus.co.uk Listed by Abyss Ransomware Group

Concertus Design and Property Consultants appeared on the Abyss ransomware group's leak site on December 05, 2023, with the attackers claiming to have exfiltrated 1.9TB of uncompressed internal files from the UK-based firm.

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Details in the Leak Listing

The Abyss leak site entry states that Concertus suffered a ransomware attack in which internal files were exfiltrated. The listing does not specify the exact types of data taken beyond describing them as internal files, nor does it disclose the number of individuals whose information may be exposed. It simply presents the company name, the volume of data (1.9TB uncompressed), and a countdown timer typical of extortion campaigns. Public reporting on Abyss indicates the group follows a double-extortion model: encrypting systems where possible and threatening to publish stolen data if ransom demands are not met.

Why This Matters for You and Your Family

When a company like Concertus that handles design, architecture, and property consultancy work is breached, the information at risk often includes details about clients, employees, suppliers, and ongoing projects. If your name, address, phone number, email, or financial records appear in those files, the exposure can lead to identity theft, phishing campaigns tailored against you, or fraud attempts that affect your household. Even when the leak site does not quantify affected records, the 1.9TB of uncompressed data suggests a substantial volume of business documents that routinely contain personal information about ordinary people.

Doxxing and Identity-Chain Risks

Stolen internal files frequently contain spreadsheets, contracts, emails, and project folders that link names to addresses, phone numbers, dates of birth, and sometimes National Insurance numbers. Attackers and subsequent data resellers can combine these fragments with other breaches to build detailed profiles. A single leaked work email can chain to your personal accounts, while an exposed home address from a property consultancy file can surface in doxxing databases. These identity chains often reach family members, including children whose details appear on school forms, medical consents, or family-linked projects.

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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 Abyss · 92 incidents tracked →

Severity High the filing does not enumerate what was exposed

Disclosed December 05, 2023

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

Abyss — 92 incidents tracked

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

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