Disclosure context

About everest

Everest is a financially-motivated ransomware group that emerged in September 2021, operating with a focus on profit-driven extortion campaigns against organizations primarily in the United States and Europe. The group's country of origin and specific affiliations remain undocumented in public threat intelligence reporting, though their operational patterns suggest they likely operate as an independent entity rather than a formal ransomware-as-a-service model. Limited public documentation exists regarding Everest's specific attack methodologies, initial access vectors, or technical capabilities, though their victim profile indicates they employ standard ransomware tactics targeting a diverse range of sectors including healthcare, technology, business services, and manufacturing organizations. Since their emergence, Everest has claimed responsibility for attacks against 339 victims across multiple countries, with the United States, United Kingdom, Italy, Germany, and Spain representing their primary geographic targets, though no specific high-profile incidents or major ransoms have been publicly documented by law enforcement or major security firms. As of current reporting, Everest appears to remain an active threat actor, though the limited public intelligence available suggests they operate as a lower-tier ransomware group compared to more prominent and well-documented criminal organizations. The group has been linked to 360 public disclosures across our corpus. First observed on a leak site on September 9, 2021; most recent post May 7, 2026. The operation is currently active.

Timeline of this disclosure

May 3, 2026Fiserv listed by evereston the group's public leak site

Sector and geography

This disclosure adds to ransomware activity in the Financial Services sector, which has 516 disclosures indexed across all operators we track. Geographically, Fiserv is reported in US, a country with 2,713 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

Fiserv

Claimed by everest · listed 18 days ago

18d

Age

since listed · data leaked

Status timeline

Listed
May 3, 2026
Data leaked

At a glance

Group: everest
Status: Data leaked
Country: US
Sector: Financial Services
Listed on leak site: May 3, 2026

About the victim

AI dossier — public-source company profile

Fiserv is a global financial technology company and one of the largest fintech providers in the world, headquartered in Brookfield, Wisconsin. It delivers core banking systems, digital banking platforms, payment processing, and merchant acquiring services to banks, credit unions, retailers, businesses, and government entities worldwide. The company serves 70% of the world's leading brands and reaches 100% of U.S. households through its financial infrastructure.

Industry: Financial Services Technology & Payment Processing
Address: 255 Fiserv Drive, Brookfield, Wisconsin 53045, United States
Employees: 40000
Founded: 1984

Attack summary

Severity: critical — Fiserv is core financial infrastructure for thousands of banks, credit unions, and merchants globally, processing payments and banking data at massive scale. A confirmed data publication by a ransomware group against such a systemically important fintech operator constitutes a critical disclosure, with likely exposure of regulated financial PII and sensitive institutional data at scale.

The Everest ransomware group claims to have compromised Fiserv and has published data (disclosed status: data_published), indicating exfiltration of company data; no ransom amount or specific data volume was stated in the post.

critical

Data the group says was taken

AI dossier — extracted from the leak post

Financial services technology data
Payment processing records
Banking platform data
Merchant and corporate client records
Internal business documents

Original description

AI-summarised, not from the leak post

Fiserv is a global financial technology company headquartered in Milwaukee, Wisconsin, United States. It provides financial services technology solutions including payment processing, core banking systems, digital banking platforms, and merchant acquiring services. Serving banks, credit unions, retailers, and businesses worldwide, Fiserv operates across the fintech and banking technology industry and is one of the largest providers of financial services infrastructure globally.

The leak post

captured from the group's site

© 2026, All rights reserved
Citizens Bank - Database Leaked 
Evaluate a Norstella company - Database Leaked 
Studio Marchi - Studio Professionale Associato - Database Leaked 
Super AI - Database Leaked 
Complete Aircraft Group - Database Leaked 
Umiles Group - Database Leaked 
K Subsea Group - Database Leaked 
Parque Eólico Toabré - Database Leaked 
PT Brantas Abipraya - Database Leaked 
Straight Line Logistics - Database Leaked 
First Priority Group - Database Leaked 
Hyundai Elevator - Database Leaked 
UD Trucks - Database Leaked 
McDonalds India - Database Leaked 
Tsunami Tsolutions - Database Leaked 
Atlas Air: MUSE INSECURE - Database Leaked 
Iron Mountain - Database Leaked 
Hosowaka Micron Group - Database Leaked 
Shinwa Co Ltd - Database Leaked 
SIGMA Processing Group - Database Leaked 
Acu Trans Solutions LLC - Database Leaked 
GIBSIN Engineers - Database Leaked 
ASRock Rack - Database Leaked 
Reeves Information Technology - Database Leaked 
WANCHI STEEL INDUSTRIAL - Database Leaked 
GC Accounting - Database Leaked 
National Money Mart Company - Database leaked 
Virginia Records - Database Leaked 
Morgan Records Management - Database leaked 
ELC Electroconsult SpA - Databas…

Sources

Victim sitefiserv.com
Leak posthttp://ransomocmou6mnbquqz44ewosbkjk3o5qjsl3orawojexfook2j7esad.onion/news/Fiserv/

Source

Indexed 18 days 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.