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Mailchimp

Claimed by Everest · listed 1 year ago

11m
Age
since listed · data leaked

Status timeline

  1. ListedJul 31, 2025
  2. Data leakeddate unknown

At a glance

Group
Everest
Status
Data leaked
Country
United States
Sector
Technology
Listed on leak site
Jul 31, 2025

About the victim

AI dossier — public-source company profile

Mailchimp is a marketing automation platform and email marketing service that enables businesses of all sizes to design, schedule, and manage email campaigns. The platform offers audience segmentation, dynamic content, analytics, website building, and landing page creation tools, along with SMS marketing and AI-powered marketing automation features.

Industry
Marketing Automation & Email Services

Attack summary

Severity: low — Post is a listing/announcement only with no proof files, no specific data inventory disclosed, no claim of exfiltration, and no operational disruption stated. No verifiable evidence of compromise presented.

The Everest group claims to have compromised Mailchimp; however, the leak post contains only a generic description of the company's services with no specific details about data exfiltrated, attack vectors, or operational impact.

low

Original description

AI-summarised, not from the leak post

Mailchimp is a leading marketing automation platform and an email marketing service. The platform allows businesses to design, schedule, and manage email campaigns, from large to small scale. With additional features like audience segmentation, dynamic content, and analytics, it caters to businesses looking to turn their audience data into actionable insights. It also grants users the ability to build websites and landing pages.

Sources

Source

Indexed 1 year 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 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 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.

Timeline of this disclosure

  • July 31, 2025Mailchimp listed by Evereston the group's public leak site

Other recent disclosures by Everest

Everest has been linked to 369 public victims on Darkfield. A sample of the most recent:

See the full Everest dossier →

Sector and geography

This disclosure adds to ransomware activity in the Technology sector, which has 3,549 disclosures indexed across all operators we track. Geographically, Mailchimp 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 Mailchimp 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.