Hennessy Advisors Reports Data Breach Impacting Sensitive Personal Information
Hennessy Advisors recently disclosed a data breach to the Maine Attorney General, revealing that unauthorized access to its systems may have compromised sensitive personal identifiable information (PII). The incident was detected on March 30, 2025, when the firm identified suspicious activity affecting certain systems and data. An investigation was launched to assess the scope and nature of the breach.
The probe confirmed that an unauthorized third party accessed sensitive data, prompting Hennessy Advisors to review the impacted information and identify affected individuals. The exposed data varies by individual but may include names, Social Security numbers, financial account details, and driver’s license information.
On February 23, 2026, Hennessy Advisors began notifying impacted individuals via mail, providing details on the specific data exposed and offering complimentary credit monitoring services. The breach notice filed with the Maine Attorney General outlines the incident’s timeline and response measures.
Source: https://straussborrelli.com/2026/02/25/hennessy-advisors-data-breach-investigation/
Hennessy Advisors, Inc. cybersecurity rating report: https://www.rankiteo.com/company/hennessy-advisors-inc.
"id": "HEN1772058976",
"linkid": "hennessy-advisors-inc.",
"type": "Breach",
"date": "3/2025",
"severity": "85",
"impact": "4",
"explanation": "Attack with significant impact with customers data leaks"{'affected_entities': [{'industry': 'Investment Management',
'name': 'Hennessy Advisors',
'type': 'Financial Services'}],
'customer_advisories': 'Notification via mail with details on exposed data '
'and complimentary credit monitoring services',
'data_breach': {'personally_identifiable_information': 'Yes',
'sensitivity_of_data': 'High',
'type_of_data_compromised': ['Names',
'Social Security numbers',
'Financial account details',
'Driver’s license information']},
'date_detected': '2025-03-30',
'date_publicly_disclosed': '2026-02-23',
'description': 'Hennessy Advisors disclosed a data breach where unauthorized '
'access to its systems may have compromised sensitive personal '
'identifiable information (PII). The incident was detected on '
'March 30, 2025, and an investigation confirmed unauthorized '
'access to sensitive data, including names, Social Security '
'numbers, financial account details, and driver’s license '
'information.',
'impact': {'data_compromised': 'Sensitive personal identifiable information '
'(PII)',
'identity_theft_risk': 'High',
'payment_information_risk': 'High'},
'investigation_status': 'Completed',
'references': [{'source': 'Maine Attorney General'}],
'regulatory_compliance': {'regulatory_notifications': 'Filed with the Maine '
'Attorney General'},
'response': {'communication_strategy': 'Notification via mail to impacted '
'individuals, offering complimentary '
'credit monitoring services'},
'threat_actor': 'Unauthorized third party',
'title': 'Hennessy Advisors Data Breach Impacting Sensitive Personal '
'Information',
'type': 'Data Breach'}