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 369 public disclosures across our corpus. First observed on a leak site on September 9, 2021; most recent post May 29, 2026. The operation is currently active.
Sector and geography
Geographically, Fishman, Larsen & Callister - Full leak published is reported in United States, a country with 11,033 ransomware disclosures in our corpus.
If your organisation is affected
A listing by Everest means Fishman, Larsen & Callister - Full leak published 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, CISA (United States), as required for your jurisdiction.
- Monitor for the data appearing on Everest'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.
