Was Teleos Systems hit by ransomware?

Teleos Systems was listed by the thegentlemen 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 thegentlemen ransomware group?

thegentlemen 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 Teleos Systems breach?

thegentlemen published data attributed to Teleos Systems. Darkfield captured the leak post and a screenshot of the listing.

Ransomware victim disclosure

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Teleos Systems

Claimed by Thegentlemen · listed 2 months ago

54d

Age

since listed · data leaked

Status timeline

ListedApr 19, 2026
Data leakeddate unknown

At a glance

Group: Thegentlemen
Status: Data leaked
Country: United Kingdom
Sector: Technology
Listed on leak site: Apr 19, 2026

About the victim

AI dossier — public-source company profile

Teleos Systems Limited is a UK-based, privately owned software company founded on 14 November 1997, headquartered in St. Neots, Cambridgeshire, with a support and development centre in Birmingham. The company develops and supports Veterinary Practice Management Systems (VPMS) and claims to be the largest independent supplier of such systems in the UK and Ireland. It serves both small independent veterinary practices and large multi-site veterinary groups.

Industry: Veterinary Practice Management Software
Address: Sales & Administration Office: Cambrian House, East Street, St Neots, Cambs, PE19 1JU, UK; Support & Training Centre: 319 Fort Dunlop, Fort Parkway, Birmingham B24 9FD, UK
Founded: 1997

Attack summary

Severity: high — Data has been confirmed published by the threat actor. Teleos Systems serves as a software supplier to veterinary practices across the UK and Ireland, meaning exfiltrated data likely includes client practice records and potentially patient/animal owner PII from their VPMS platform, representing significant downstream exposure for many third-party practices.

The group 'thegentlemen' has disclosed data from Teleos Systems Limited, with the post marked as data_published, indicating exfiltration and publication of company data. No ransom amount or specific data volume was stated, but the disclosure status confirms data has been released.

high

Data the group says was taken

AI dossier — extracted from the leak post

Veterinary practice client data
Practice management software data
Business operational data

What the group claims

teleosvet.co.uk Teleos Systems Limited is a UK-based software company founded on 14 November 1997, headquartered in St. Neots, Cambridgeshire, and is the largest independent supplier of Veterinary Practice Management Systems (VPMS) in the UK and Ireland. The company has been developing and supporting its flagship veterinary management software for over 20 years, serving small independent practices as well as large multi-site veterinary groups.

Sources

Victim siteteleosvet.co.uk

Source

Indexed 2 months 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 thegentlemen

thegentlemen is a ransomware group that emerged in September 2025, operating with apparent financial motivations based on their broad targeting of commercial sectors. The group has documented 267 victims across multiple countries, with primary focus on the United States, Thailand, France, Brazil, and India. Their targeting strategy demonstrates a preference for high-value sectors including manufacturing, technology, healthcare, and financial services organizations. Given the group's recent emergence and limited public documentation from established threat intelligence sources such as CISA, FBI, or major security research firms, specific details regarding their country of origin, operational structure, attack methodologies, encryption techniques, and whether they employ ransomware-as-a-service models remain unclear. The relatively high victim count of 267 in a short operational timeframe since September 2025 suggests either an aggressive campaign pace or potential inflation of victim numbers through affiliate operations, though without corroborating intelligence reports, the group's exact operational capabilities and notable campaigns cannot be definitively established. Current intelligence indicates the group remains active as of late 2025, though comprehensive threat profiling requires additional validated reporting from authoritative cybersecurity sources. The group has been linked to 483 public disclosures across our corpus. First observed on a leak site on September 9, 2025; most recent post June 11, 2026. The operation is currently active.

Also tracked as: the gentlemen.

Timeline of this disclosure

April 19, 2026Teleos Systems listed by thegentlemenon the group's public leak site

Other recent disclosures by thegentlemen

thegentlemen has been linked to 483 public victims on Darkfield. A sample of the most recent:

See the full thegentlemen dossier →

Sector and geography

This disclosure adds to ransomware activity in the Technology sector, which has 2,526 disclosures indexed across all operators we track. Geographically, Teleos Systems is reported in United Kingdom, a country with 309 ransomware disclosures in our corpus.

If your organisation is affected

A listing by thegentlemen means Teleos Systems 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.
Monitor for the data appearing on thegentlemen'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.