HarbisonWalker International Data Breach Under Investigation Following Exposure of Sensitive Personal Data
On September 29, 2026, national class action law firm Edelson Lechtzin LLP announced an investigation into a data breach at HarbisonWalker International (HWI), the largest U.S. supplier of refractory products and heat-resistant materials, based in Pittsburgh, Pennsylvania.
HWI detected suspicious activity on its internal network and began notifying affected individuals after securing its systems. The breach may have exposed highly sensitive data, including names, addresses, Social Security numbers, driver’s licenses and government-issued IDs, financial account details, medical records, and health insurance information. Due to the breadth of compromised data, impacted individuals face elevated risks of identity theft, financial fraud, medical fraud, and targeted phishing attacks.
While HWI reported the breach to regulators in Massachusetts, Texas, and Vermont on September 22, 2026, key details such as the timeline of the incident and the attack vector remain undisclosed. At least 56 Massachusetts residents are confirmed to be affected, though the total number of impacted individuals nationwide is still unknown.
Edelson Lechtzin LLP is examining whether HWI implemented adequate cybersecurity measures and whether additional safeguards could have mitigated the breach. The firm is offering free case evaluations to affected individuals to assess potential legal claims. Those who received a breach notification are advised to preserve documentation and enroll in complimentary credit monitoring before the December 31, 2026 deadline.
HarbisonWalker International cybersecurity rating report: https://www.rankiteo.com/company/hwi-amemberofcalderys
"id": "HWI1790713529",
"linkid": "hwi-amemberofcalderys",
"type": "Breach",
"date": "9/2026",
"severity": "85",
"impact": "4",
"explanation": "Attack with significant impact with customers data leaks"{'affected_entities': [{'customers_affected': 'At least 56 Massachusetts '
'residents (total unknown)',
'industry': 'Refractory products and heat-resistant '
'materials',
'location': 'Pittsburgh, Pennsylvania, USA',
'name': 'HarbisonWalker International (HWI)',
'type': 'Corporation'}],
'customer_advisories': 'Affected individuals notified; advised to enroll in '
'credit monitoring and preserve documentation',
'data_breach': {'personally_identifiable_information': 'Names, addresses, '
'Social Security '
'numbers, driver’s '
'licenses and '
'government-issued IDs',
'sensitivity_of_data': 'High',
'type_of_data_compromised': ['Personally Identifiable '
'Information (PII)',
'Financial account details',
'Medical records',
'Health insurance information']},
'date_detected': '2026-09-22',
'date_publicly_disclosed': '2026-09-29',
'description': 'On September 29, 2026, national class action law firm Edelson '
'Lechtzin LLP announced an investigation into a data breach at '
'HarbisonWalker International (HWI), the largest U.S. supplier '
'of refractory products and heat-resistant materials. HWI '
'detected suspicious activity on its internal network and '
'began notifying affected individuals after securing its '
'systems. The breach may have exposed highly sensitive data, '
'including names, addresses, Social Security numbers, driver’s '
'licenses and government-issued IDs, financial account '
'details, medical records, and health insurance information. '
'Impacted individuals face elevated risks of identity theft, '
'financial fraud, medical fraud, and targeted phishing '
'attacks.',
'impact': {'data_compromised': 'Highly sensitive personal data including '
'names, addresses, Social Security numbers, '
'driver’s licenses and government-issued IDs, '
'financial account details, medical records, '
'and health insurance information',
'identity_theft_risk': 'Elevated',
'legal_liabilities': 'Potential legal claims under investigation',
'payment_information_risk': 'Elevated',
'systems_affected': 'Internal network'},
'investigation_status': 'Under investigation',
'recommendations': 'Affected individuals advised to preserve documentation '
'and enroll in complimentary credit monitoring before '
'December 31, 2026',
'references': [{'source': 'Edelson Lechtzin LLP'}],
'regulatory_compliance': {'legal_actions': 'Class action investigation by '
'Edelson Lechtzin LLP',
'regulatory_notifications': ['Massachusetts',
'Texas',
'Vermont']},
'response': {'communication_strategy': 'Breach notifications sent to affected '
'individuals and regulators',
'containment_measures': 'Systems secured',
'incident_response_plan_activated': 'Yes'},
'title': 'HarbisonWalker International Data Breach Under Investigation '
'Following Exposure of Sensitive Personal Data',
'type': 'Data Breach'}