Was CI Engineering hit by ransomware?

CI Engineering was listed by the Cicada3301 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 Cicada3301 ransomware group?

Cicada3301 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 CI Engineering breach?

Cicada3301 published data attributed to CI Engineering (~700 GB). Darkfield captured the leak post and a screenshot of the listing.

Ransomware victim disclosure

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C&I Engineering

listed as CI Engineering · Claimed by Cicada3301 · listed 10 months ago

700 GB

Data size

10m

Age

since listed · data leaked

Status timeline

ListedSep 4, 2025
Data leakeddate unknown

At a glance

Group: Cicada3301
Status: Data leaked
Country: United States
Listed on leak site: Sep 4, 2025
Data size: 700 GB

About the victim

AI dossier — public-source company profile

C&I Engineering is a 100% employee-owned comprehensive engineering firm with over 40 years of history, serving industries including chemical, refining, food & beverage, distilled spirits, and utilities. The firm offers a broad range of services spanning civil & structural, mechanical, piping design, power & controls, process engineering, project management, laser scanning, and drone imaging. Clients include major companies such as Jim Beam, Nestle, Marathon Petroleum, and Hunt Refining Company.

Industry: Multi-discipline Industrial & Process Engineering Services
Employees: 51-200

Attack summary

Severity: high — 700 GB of confirmed exfiltrated data from an engineering firm serving critical industrial sectors (refining, chemical, utilities) represents significant business and potentially sensitive project/infrastructure data exposure; data has been published rather than merely threatened.

Cicada3301 claims to have exfiltrated approximately 700 GB of data from C&I Engineering, with the leak post indicating the data has been published ('disclosed status: data_published'). No ransom amount was stated and no specific data categories were enumerated in the post.

high

Data the group says was taken

AI dossier — extracted from the leak post

Engineering project files
Business data (700 GB exfiltrated)

What the group claims

Status: 0d 23h 23m 40s - Size Data: 700 GB

Sources

Victim sitewww.cieng.com
Leak posthttp://cicadabv7vicyvgz5khl7v2x5yygcgow7ryy6yppwmxii4eoobdaztqd.onion/q8qo8wxzlpbn14ixav7k58l5vtzjf4ik

Source

Indexed 10 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 Cicada3301

Cicada3301 is a recently emerged ransomware group that began operations in June 2024, primarily motivated by financial gain through extortion activities targeting organizations across multiple sectors. The group's origin and affiliations remain largely undocumented in public threat intelligence reporting, with limited information available regarding their operational structure or potential connections to other cybercriminal organizations. Based on observed targeting patterns, Cicada3301 has demonstrated a preference for attacking business services, technology, manufacturing, and financial sector organizations, with their operations concentrated primarily in English-speaking countries including the United States, United Kingdom, and Canada, as well as extending to Spain and Singapore. The group has successfully compromised approximately 75 known victims since their emergence, though specific details regarding their attack methodologies, initial access vectors, encryption techniques, and extortion tactics have not been extensively documented in publicly available threat intelligence reports from major cybersecurity firms or government agencies. Given the limited public documentation available from CISA, FBI, Mandiant, or other reputable security researchers, the group's current operational status, technical capabilities, and specific attack infrastructure remain largely uncharacterized in open-source intelligence reporting. As of the most recent observations, Cicada3301 appears to remain active in conducting ransomware operations, though comprehensive analysis of their tactics, techniques, and procedures awaits more detailed public reporting from established threat intelligence sources. The group has been linked to 75 public disclosures across our corpus. First observed on a leak site on June 20, 2024; most recent post September 4, 2025. The operation is currently inactive.

Timeline of this disclosure

September 4, 2025CI Engineering listed by Cicada3301on the group's public leak site

Data size: 700 GB

Other recent disclosures by Cicada3301

Cicada3301 has been linked to 75 public victims on Darkfield. A sample of the most recent:

See the full Cicada3301 dossier →

Sector and geography

Geographically, CI Engineering is reported in United States, a country with 11,033 ransomware disclosures in our corpus.

If your organisation is affected

A listing by Cicada3301 means CI Engineering 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 Cicada3301'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.