Eisner Advisory Group Data Breach Investigation
The data breach attorneys at The Lyon Firm are reviewing new claims of data theft for plaintiffs nationwide. If you have been contacted by Eisner Advisory Group (EisnerAmper) regarding a recent security breach, if it important to understand the increased risks of fraud and identity theft. Contact our legal team to discuss possible legal action and to understand how the class action process works. Free consultations and case reviews.
What Happened at Eisner Advisory Group?
According to a data breach notice provided by the company, In September 2023, Eisner Advisory Group LLC reportedly experienced a data breach that may have compromised certain sensitive personal information for a large number of individuals. The company became aware of suspicious activity and a subsequent investigation concluded that unauthorized access occurred between September 4, 2023, and September 9, 2023.
After the company was aware that an unauthorized actor gained access to certain files and personal data, Eisner Advisory apparently did not complete its review until February 2025. Eisner started notifying individuals in April 2025. It is unclear why it took so long to alert potential victims of this incident.
The types of personal data that may have been compromised include the following:
- Name
- Address
- Social Security number
- Driver’s license number or state-issued identification number
- Passport number
- Date of birth
- Financial account information
- Payment card information
- Medical information
- Health insurance information
Eisner Advisory Group LLC is a New York accounting and business consulting firm operating under the EisnerAmper brand. The company provides risk management, financial advisory, tax planning, and compliance solutions.