Was concertus.co.uk hit by ransomware?

concertus.co.uk was listed by the Abyss ransomware operation (United Kingdom), 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 Abyss ransomware group?

Abyss 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 concertus.co.uk breach?

Abyss published data attributed to concertus.co.uk (~1.9 TB). Darkfield captured the leak post and a screenshot of the listing.

Ransomware victim disclosure

← All victims

Concertus Design and Property Consultants

listed as concertus.co.uk · Claimed by Abyss · listed 3 years ago

1.9 TB

Data size

31m

Age

since listed · data leaked

Status timeline

ListedDec 5, 2023
Data leakeddate unknown

At a glance

Group: Abyss
Status: Data leaked
Country: United Kingdom
Sector: Construction
Listed on leak site: Dec 5, 2023
Data size: 1.9 TB

About the victim

AI dossier — public-source company profile

Concertus Design and Property Consultants is a multi-disciplinary design and property consultancy based in Suffolk and Derbyshire, United Kingdom. The firm specialises in delivering construction projects across sectors including education, healthcare, blue light services, and care homes. Services span architecture, structural engineering, quantity surveying, project management, and carbon consultancy for both public and private sector clients.

Industry: Architecture & Property Consultancy
Address: Marigold House, Suffolk, United Kingdom (also offices in Derbyshire)

Attack summary

Severity: high — 1.9 TB of data has been confirmed exfiltrated and published. The firm works extensively with public sector clients including schools, healthcare facilities, fire and police stations, and ambulance hubs, meaning the data likely contains sensitive project, personnel, and infrastructure details relevant to critical public services.

The Abyss ransomware group claims to have exfiltrated 1.9 TB of uncompressed data from Concertus Design and Property Consultants, with the data now published. No ransom figure was stated.

high

Data the group says was taken

AI dossier — extracted from the leak post

Project design files
Property consultancy records
Client and contract documentation
Estates and development management data
Health and safety / CDM records
Financial and cost consultancy data
Internal business records

What the group claims

Concertus Design and Property Consultants 1,9Tb uncompressed data

Sources

Victim siteconcertus.co.uk

Source

Indexed 3 years 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 Abyss

Abyss is a relatively new ransomware group that emerged in March 2023, operating with primarily financial motivations and targeting organizations across multiple sectors with a focus on English-speaking countries. The group's origin and affiliations remain largely undocumented by major security agencies, though their targeting patterns suggest they operate independently rather than as a Ransomware-as-a-Service model. Their attack methodology and specific tools have not been extensively documented by major threat intelligence firms, though their victim profile of 87 organizations indicates they employ effective initial access techniques to compromise business services, technology, healthcare, and agriculture sectors. The group demonstrates a clear geographic preference for targets in the United States, United Kingdom, Canada, Switzerland, and Hong Kong, suggesting either language preferences or specific regional access capabilities. Due to the group's recent emergence and relatively limited public documentation from established security researchers, detailed information about notable campaigns, encryption methods, or law enforcement actions remains scarce. Abyss appears to remain active as of current reporting, though the lack of extensive public analysis by major threat intelligence organizations suggests they may operate at a smaller scale compared to more prominent ransomware families. The group has been linked to 103 public disclosures across our corpus. First observed on a leak site on March 21, 2023; most recent post June 7, 2026. The operation is currently active.

Timeline of this disclosure

December 5, 2023concertus.co.uk listed by Abysson the group's public leak site

Data size: 1.9 TB

Other recent disclosures by Abyss

Abyss has been linked to 103 public victims on Darkfield. A sample of the most recent:

See the full Abyss 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, concertus.co.uk is reported in United Kingdom, a country with 1,217 ransomware disclosures in our corpus.

If your organisation is affected

A listing by Abyss means concertus.co.uk 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, NCSC (United Kingdom), as required for your jurisdiction.
Monitor for the data appearing on Abyss'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.