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, 2025Shelbourne Accountants listed by cephaluson the group's public leak site

Sector and geography

This disclosure adds to ransomware activity in the Financial Services sector, which has 516 disclosures indexed across all operators we track. Geographically, Shelbourne Accountants is reported in IE, a country with 5 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

Shelbourne Accountants

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: IE
Sector: Financial Services
Listed on leak site: Aug 29, 2025

About the victim

AI dossier — public-source company profile

Shelbourne Accountants is an accounting firm based in Dublin, Ireland, operating under the domain shelbourneaccountants.ie. The firm offers accounting, tax, and related financial services to clients in the Dublin area. It is described among top accounting firms in Dublin on its public website.

Industry: Accounting & Tax Services
Address: Dublin, Ireland

Attack summary

Severity: medium — The victim is an accounting firm handling sensitive financial and tax data for clients, which carries high inherent sensitivity; however, the leak post contains no proof, no confirmed exfiltration details, and no data volume is stated — only a 'coming soon' announcement with a disclosed status of data_published.

The ransomware group 'cephalus' has listed Shelbourne Accountants as a victim with a 'coming soon' disclosure, indicating data publication is pending or in progress; no specific details about encrypted or exfiltrated data have been provided in the leak post.

medium

Data the group says was taken

AI dossier — extracted from the leak post

Client financial records
Tax documentation
Business accounting data

What the group claims

coming soon...

Sources

Victim siteshelbourneaccountants.ie

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.