Disclosure context

About killsec

killsec is a relatively new ransomware group that emerged in March 2024, operating with apparent financial motivations and demonstrating broad targeting across multiple geographic regions and industry sectors. The group's origin and potential state affiliations remain unclear due to limited public documentation from major threat intelligence sources, though their targeting pattern suggests opportunistic rather than geopolitically motivated operations. With 276 documented victims primarily concentrated in the United States, India, the United Kingdom, Brazil, and Belgium, killsec appears to focus heavily on healthcare, technology, business services, and financial sectors, indicating either specific tooling designed for these environments or opportunistic targeting of organizations with valuable data and high pressure to restore operations quickly. Given the group's recent emergence and the lack of detailed technical analysis from established cybersecurity firms like Mandiant or law enforcement advisories from CISA or FBI, specific details about their attack methodology, initial access vectors, encryption techniques, and extortion tactics have not been publicly documented in authoritative sources. The group remains active as of current reporting, though the limited intelligence profile suggests they may be either a smaller operation or one that has not yet attracted significant attention from major threat intelligence organizations despite their substantial victim count. The group has been linked to 279 public disclosures across our corpus. First observed on a leak site on March 21, 2024; most recent post May 14, 2026. The operation is currently active.

Timeline of this disclosure

March 17, 2026hospitalvetdiadema24h.com.br listed by killsecon the group's public leak site

Sector and geography

This disclosure adds to ransomware activity in the Healthcare sector, which has 1,779 disclosures indexed across all operators we track. Geographically, hospitalvetdiadema24h.com.br is reported in Brazil, a country with 319 ransomware disclosures in our corpus.

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.

Ransomware victim disclosure

← All victims

Hospital Veterinário Diadema 24h

listed as hospitalvetdiadema24h.com.br · Claimed by killsec · listed 2 months ago

Age

since listed · data leaked

Status timeline

Listed
Mar 17, 2026
Data leaked

At a glance

Group: killsec
Status: Data leaked
Country: Brazil
Sector: Healthcare
Listed on leak site: Mar 17, 2026

About the victim

AI dossier — public-source company profile

Hospital Veterinário Diadema 24h is a 24-hour veterinary hospital located in Diadema, São Paulo, Brazil. The facility provides round-the-clock emergency and routine veterinary care for animals. The organisation operates within the Brazilian private healthcare sector.

Industry: Veterinary Healthcare Services
Address: Diadema, São Paulo, Brazil

Attack summary

Severity: medium — Data is marked as published by a known ransomware group targeting a healthcare entity, which typically involves sensitive patient and business records, but the leak post provides no proof files, no data size, and no specific data categories, limiting severity assessment.

The KillSec ransomware group claims an attack against the organisation with a data disclosure status of 'data_published', suggesting exfiltration of data. The leak post provides minimal detail, listing a price as unknown and one pending disclosure.

medium

Data the group says was taken

AI dossier — extracted from the leak post

Unspecified exfiltrated data

What the group claims

Price ??? Disclosures 0/1

Sources

Victim siteexample.com

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.