Disclosure context

About cephalus

Based on available public information, Cephalus is a recently emerged ransomware group first observed in August 2025, operating with apparent financial motivations targeting organizations primarily across the United States, United Kingdom, Netherlands, and Ireland. The group has claimed 19 victims since emergence, with no publicly documented country of origin or confirmed affiliations to established ransomware families or RaaS operations by major security researchers or government agencies. Their attack methodology and specific technical capabilities remain largely undocumented in public threat intelligence reporting, though their targeting pattern shows focus on healthcare, business services, financial services, and manufacturing sectors alongside organizations of undetermined industry classification. No major high-profile campaigns, record ransom demands, or law enforcement disruption actions have been publicly reported by CISA, FBI, or established security research firms at this time. The group appears to remain active as of current reporting, though the limited public documentation suggests either highly targeted operations or insufficient analysis coverage by major threat intelligence organizations. The group has been linked to 19 public disclosures across our corpus. First observed on a leak site on August 26, 2025; most recent post August 29, 2025. The operation is currently inactive.

Timeline of this disclosure

August 29, 2025Delta Information Systems listed by cephaluson the group's public leak site

Sector and geography

This disclosure adds to ransomware activity in the Technology sector, which has 2,524 disclosures indexed across all operators we track. Geographically, Delta Information Systems 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

← All victims

Acroamatics

listed as Delta Information Systems · Claimed by cephalus · listed 9 months ago

Age

since listed · data leaked

Status timeline

Listed
Aug 29, 2025
Data leaked

At a glance

Group: cephalus
Status: Data leaked
Country: United States
Sector: Technology
Listed on leak site: Aug 29, 2025

About the victim

AI dossier — public-source company profile

Acroamatics (acroamatics.com) appears to be a technology and systems engineering firm operating in the United States, likely serving defense, intelligence, or government sectors based on its domain and association with Delta Information Systems. The victim name 'Delta Information Systems' may refer to a division, subsidiary, or related entity. Specific operational details are unavailable due to absence of public site content.

Industry: Defense & Intelligence Software / Systems Engineering

Attack summary

Severity: critical — Exfiltration of 800+ GB of proprietary software and hardware code from what appears to be a defense/intelligence-adjacent technology firm, with the attacker actively soliciting buyers for the stolen code, represents a critical intellectual property and potential national security exposure.

The group claims to have exfiltrated over 800 GB of internal data including software and hardware source code, and is advertising the stolen code for sale to interested buyers. No encryption claim is explicitly stated; the post focuses on data theft and monetisation.

critical

Data the group says was taken

AI dossier — extracted from the leak post

Software source code
Hardware code/designs
Internal business data (800 GB+)

What the group claims

We have got all the software and hardware code,and got 800G+ of internal data. The link will coming soon... Of if anyone is intersted in purchasing the code,pls contact me

Sources

Victim siteacroamatics.com

Source

Indexed 9 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.