Mosley Glick O’Brien Hit by BianLian Ransomware Attack, Exposing 1.2TB of Sensitive Data
In February 2025, Mosley Glick O’Brien Inc., a certified public accounting firm based in Maumee, Ohio, detected a ransomware attack on its systems. The breach was discovered on February 19, 2025, prompting the firm to engage internal IT teams and third-party forensic specialists to contain the incident and restore operations.
The attack was attributed to the BianLian ransomware group, which claimed to have exfiltrated 1.2TB of sensitive data, including firm and client financial records, QuickBooks data, HR files, business contracts, personally identifiable information (PII), protected health information (PHI), and email correspondence. The exposed data may have included names, Social Security numbers, driver’s license details, dates of birth, medical records, health insurance information, financial account numbers, payment card details, and tax identification numbers.
A full investigation concluded on February 24, 2026, nearly a year after the initial breach. Mosley Glick O’Brien began notifying affected individuals via written mail and posted a public notice on its website. The firm, which serves small to medium-sized businesses across industries such as construction, manufacturing, and healthcare, has been operational since 2008.
Legal firm Shamis & Gentile P.A. is now investigating the breach, with potential class action lawsuits being considered for those impacted. Affected individuals may seek compensation for damages, including identity theft monitoring costs, financial losses, and emotional distress.
Source: https://www.claimdepot.com/investigations/mosley-glick-obrien-data-breach-2026
Mosley, Pfundt, Glick & O'Brien, Inc. cybersecurity rating report: https://www.rankiteo.com/company/mosley-pfundt-glick-&-demarco-inc.
"id": "MOS1773853428",
"linkid": "mosley-pfundt-glick-&-demarco-inc.",
"type": "Ransomware",
"date": "2/2025",
"severity": "100",
"impact": "5",
"explanation": "Attack threatening the organization's existence"{'affected_entities': [{'industry': ['Construction',
'Manufacturing',
'Healthcare'],
'location': 'Maumee, Ohio',
'name': 'Mosley Glick O’Brien Inc.',
'type': 'Certified Public Accounting Firm'}],
'customer_advisories': 'Public notice on website, written mail to affected '
'individuals',
'data_breach': {'data_encryption': 'Yes',
'data_exfiltration': 'Yes',
'personally_identifiable_information': ['Names',
'Social Security '
'numbers',
'Driver’s license '
'details',
'Dates of birth',
'Medical records',
'Health insurance '
'information',
'Financial account '
'numbers',
'Payment card details',
'Tax identification '
'numbers'],
'sensitivity_of_data': 'High',
'type_of_data_compromised': ['Firm and client financial '
'records',
'QuickBooks data',
'HR files',
'Business contracts',
'Personally identifiable '
'information (PII)',
'Protected health information '
'(PHI)',
'Email correspondence']},
'date_detected': '2025-02-19',
'date_resolved': '2026-02-24',
'description': 'In February 2025, Mosley Glick O’Brien Inc., a certified '
'public accounting firm based in Maumee, Ohio, detected a '
'ransomware attack on its systems. The breach was attributed '
'to the BianLian ransomware group, which claimed to have '
'exfiltrated 1.2TB of sensitive data, including firm and '
'client financial records, QuickBooks data, HR files, business '
'contracts, personally identifiable information (PII), '
'protected health information (PHI), and email correspondence.',
'impact': {'data_compromised': '1.2TB',
'identity_theft_risk': 'High',
'legal_liabilities': 'Potential class action lawsuits',
'payment_information_risk': 'High'},
'investigation_status': 'Concluded',
'ransomware': {'data_encryption': 'Yes',
'data_exfiltration': 'Yes',
'ransomware_strain': 'BianLian'},
'regulatory_compliance': {'legal_actions': 'Potential class action lawsuits '
'(Shamis & Gentile P.A.)'},
'response': {'communication_strategy': 'Public notice on website, written '
'mail to affected individuals',
'incident_response_plan_activated': 'Yes',
'recovery_measures': 'Systems restored',
'third_party_assistance': 'Forensic specialists'},
'threat_actor': 'BianLian ransomware group',
'title': 'Mosley Glick O’Brien Hit by BianLian Ransomware Attack',
'type': 'Ransomware'}