Was ellison-mills.com hit by ransomware?

ellison-mills.com was listed by the chaos ransomware operation (United States), and stolen data was published on the group's leak site. Darkfield tracks this disclosure with the original leak post, screenshot and group context.

Who is the chaos ransomware group?

chaos is a ransomware operator tracked by Darkfield. See the full operator dossier for its known victims, sectors targeted, IOCs and leak-site infrastructure.

What data was leaked in the ellison-mills.com breach?

chaos published data attributed to ellison-mills.com. Darkfield captured the leak post and a screenshot of the listing.

Ransomware victim disclosure

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Ellison-Mills Contracting

listed as ellison-mills.com · Claimed by Chaos · listed 11 months ago

10m

Age

since listed · data leaked

Status timeline

ListedSep 1, 2025
Data leakeddate unknown

At a glance

Group: Chaos
Status: Data leaked
Country: United States
Listed on leak site: Sep 1, 2025

About the victim

AI dossier — public-source company profile

Ellison-Mills Contracting is a family-oriented heavy civil construction company specializing in wet utility and roadway infrastructure in Southern Arizona. The company delivers multi-million-dollar projects across multiple delivery methods including CMAR, Design-Build, Job Order Contracts, and Design-Bid-Build. It operates out of offices in Casa Grande and Tucson, Arizona, serving municipal and tribal government clients.

Industry: Heavy Civil Construction & Wet Utility Infrastructure
Address: 3152 N. Lear Avenue, Suite 2, Casa Grande, AZ 85122

Attack summary

Severity: medium — Data has been published, indicating confirmed exfiltration rather than a mere listing; however, the leak post provides no detail on the type or scale of data involved, and there is no indication of regulated PII, medical, financial, or government classified data at scale.

The Chaos ransomware group claims to have compromised Ellison-Mills Contracting and has published data (disclosed status: data_published), though the leak post does not explicitly detail whether encryption, exfiltration, or both occurred, nor does it specify the volume or nature of data stolen.

medium

Data the group says was taken

AI dossier — extracted from the leak post

Company business records
Project management documentation
Client/contract information
Employee records

What the group claims

Ellison-Mills Contracting is a family-oriented company specializing in wet utility and roadway infrastructure in Southern Arizona. They are committed to cultivating strong relationships with clients and team members while delivering quality construction management for various project types. With extensive experience in multimillion-dollar projects, the company prides itself on its ability to complete work on time and under budget across several contracting methods.

Sources

Source

Indexed 11 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.

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Disclosure context

About chaos

Based on the limited publicly available information, Chaos is a recently emerged ransomware group that was first observed in March 2025, appearing to be financially motivated given their ransom demands and targeting patterns. The group's origin and specific affiliations remain unclear due to their recent emergence, though their operational model and whether they operate as Ransomware-as-a-Service or as an independent entity has not been definitively established by security researchers. Their attack methodology and specific technical capabilities are not yet well-documented in public threat intelligence reports, though their targeting suggests they employ common initial access vectors to compromise victims across multiple sectors. Chaos has claimed 41 victims primarily concentrated in the United States, Germany, Poland, Malaysia, and Sweden, with a particular focus on technology companies, financial services, business services, and manufacturing sectors, though the scope and impact of their most significant attacks have not been widely publicized. The group currently appears to be active based on recent victim claims, though comprehensive analysis from major security firms regarding their long-term operational capabilities and potential law enforcement actions remains limited due to their recent emergence in the threat landscape. The group has been linked to 69 public disclosures across our corpus. First observed on a leak site on March 31, 2025; most recent post July 14, 2026. The operation is currently active.

Timeline of this disclosure

September 1, 2025ellison-mills.com listed by chaoson the group's public leak site

Other recent disclosures by chaos

chaos has been linked to 69 public victims on Darkfield. A sample of the most recent:

See the full chaos dossier →

Sector and geography

Geographically, ellison-mills.com is reported in United States, a country with 11,033 ransomware disclosures in our corpus.

If your organisation is affected

A listing by chaos means ellison-mills.com 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 chaos'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.