Was B&M - Expertise - Audit hit by ransomware?

B&M - Expertise - Audit was listed by the Cicada3301 ransomware operation (France), 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 B&M - Expertise - Audit breach?

Cicada3301 published data attributed to B&M - Expertise - Audit (~233 GB). Darkfield captured the leak post and a screenshot of the listing.

Ransomware victim disclosure

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B & M Expertise

listed as B&M - Expertise - Audit · Claimed by Cicada3301 · listed 1 year ago

233 GB

Data size

12m

Age

since listed · data leaked

Status timeline

ListedJul 18, 2025
Data leakeddate unknown

At a glance

Group: Cicada3301
Status: Data leaked
Country: France
Sector: Business Services
Listed on leak site: Jul 18, 2025
Data size: 233 GB

About the victim

AI dossier — public-source company profile

B & M Expertise is a French accounting and audit firm based in France with 26 years of operating experience. The firm provides comprehensive business services including company formation, accounting, payroll processing, financial auditing, and business advisory to approximately 300 clients. They operate with 2 partners, 4senior managers, 1 legal specialist, and 18 support staff.

Industry: Accounting & Audit Services
Employees: 25-30
Founded: 1998

Attack summary

Severity: high — Confirmed exfiltration of 233 GB of sensitive business and financial data from an accounting firm, which routinely handles regulated tax records, personal financial information, and client PII. This scale and nature of data exposure poses significant regulatory and privacy risks to the firm's ~300 clients.

Cicada3301 claims to have exfiltrated 233 GB of data from B & M Expertise. The group has published the data with no ransom demand stated, indicating a pure data-theft or vandalism-motivated attack.

high

Data the group says was taken

AI dossier — extracted from the leak post

Client accounting records
Payroll data
Financial statements
Tax documentation
Corporate formation documents
Business advisory files
Client identification documents

What the group claims

Status: 20d 19h 47m 26s - Size Data: 233 GB

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 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

July 18, 2025B&M - Expertise - Audit listed by Cicada3301on the group's public leak site

Data size: 233 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

This disclosure adds to ransomware activity in the Business Services sector, which has 3,796 disclosures indexed across all operators we track. Geographically, B&M - Expertise - Audit is reported in France, a country with 612 ransomware disclosures in our corpus.

If your organisation is affected

A listing by Cicada3301 means B&M - Expertise - Audit 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, CERT-FR (France), 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.