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

January 20, 2026Ciena listed by Evereston the group's public leak site

Sector and geography

This disclosure adds to ransomware activity in the Telecommunication sector, which has 54 disclosures indexed across all operators we track. Geographically, Ciena is reported in United States, a country with 7,392 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

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Ciena

Claimed by Everest · listed 4 months ago

Age

since listed · data leaked

Status timeline

Listed
Jan 20, 2026
Data leaked

At a glance

Group: Everest
Status: Data leaked
Country: United States
Sector: Telecommunication
Listed on leak site: Jan 20, 2026

About the victim

AI dossier — public-source company profile

Ciena Corporation is a U.S.-based networking systems, services, and software company headquartered in Hanover, Maryland. The company specializes in optical and routing technologies used by telecommunications carriers, cloud providers, and enterprises worldwide. Ciena operates globally and is publicly traded on the NYSE.

Industry: Optical Networking & Telecommunications Equipment
Address: 7035 Ridge Road, Hanover, Maryland 21076, United States
Employees: 5001-10000
Founded: 1992

Attack summary

Severity: high — Ciena is a major publicly traded telecommunications infrastructure company; a confirmed data_published status from the Everest group implies actual exfiltration and release of corporate data, which is significant given the company's scale and role in critical telecom infrastructure, even though the leaked post provides no granular data inventory.

The Everest ransomware group claims an attack on Ciena and has listed the disclosure status as data_published, indicating exfiltration and/or publication of company data; however, the leak post itself contains no substantive detail about the nature or volume of data stolen or any ransom demand.

high

Original description

AI-summarised, not from the leak post

Ciena Corporation is a US-based global supplier of telecommunications networking equipment, software, and services. The company's solutions support the delivery of voice, video, and data traffic for many of the world's largest telecom service providers. Its product portfolio includes solutions for optical transport, broadband access, data center connectivity, and software automation. It was founded in 1992 and headquartered in Hanover, Maryland.

The leak post

captured from the group's site

© 2026, All rights reserved
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Sources

Leak posthttp://ransomocmou6mnbquqz44ewosbkjk3o5qjsl3orawojexfook2j7esad.onion/news/Ciena/

Source

Indexed 4 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.