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Guerrero Mears LLP

Claimed by Cephalus · listed 11 months ago

10m
Age
since listed · data leaked

Status timeline

  1. ListedAug 26, 2025
  2. Data leakeddate unknown

At a glance

Group
Cephalus
Status
Data leaked
Country
United States
Listed on leak site
Aug 26, 2025

About the victim

AI dossier — public-source company profile

Guerrero Mears LLP is a boutique transactional law firm based in Bakersfield, California, serving the Central Valley. The firm specializes in business transactions, real estate, estate planning, and tax matters, representing clients ranging from large multinational companies to small family businesses. The firm has over 10 years of experience and employs five attorneys and four support staff.

Industry
Boutique Transactional Law Firm
Address
5016 California Avenue, Second Floor, Suite 7, Bakersfield, California 93309
Employees
1-10

Attack summary

Severity: high — As a law firm, Guerrero Mears LLP likely holds highly sensitive and legally privileged client data including financial records, estate plans, tax documents, and business transaction files for individuals and companies. Confirmed data publication constitutes a significant breach of confidential and potentially regulated information.

The group 'cephalus' claims to have exfiltrated data from Guerrero Mears LLP and has published the data; the size of the exfiltrated data was not recorded. No encryption claim is stated.

high

Data the group says was taken

AI dossier — extracted from the leak post
  • Client legal files
  • Business transaction documents
  • Estate planning documents
  • Tax records
  • Real estate transaction records
  • Potentially privileged attorney-client communications

What the group claims

Guerrero Mears LLP DATALEAK | (FORGOT THE SIZE)

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 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 26, 2025Guerrero Mears LLP listed by cephaluson the group's public leak site

Other recent disclosures by cephalus

cephalus has been linked to 19 public victims on Darkfield. A sample of the most recent:

See the full cephalus dossier →

Sector and geography

Geographically, Guerrero Mears LLP is reported in United States, a country with 11,033 ransomware disclosures in our corpus.

If your organisation is affected

A listing by cephalus means Guerrero Mears LLP 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 cephalus'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.