Accounting firm took over a year to inform users of data breach

Sax, a US-based accounting firm, suffered a data breach that exposed the personal information of nearly 250,000 individuals. However, the affected only learned about their fate 18 months later.

The accounting firm suffered a data breach in late July 2024, noticing unauthorized activity in its systems a week later, according to the company’s data breach notice.

According to Sax, in response, the company took measures to ensure its systems were secure and also “initiated an investigation to determine the full nature and scope of the event.”

The company explained that it followed the classic rulebook in dealing with similar situations: Sax engaged cybersecurity experts to assist with the investigation and hired third parties to review the exposed data.

What’s not so common is how long the review took. According to the data breach notice, the company concluded its investigation on December 1st, 2025, nearly 18 months after the data breach was discovered.

Information the company disclosed to the Maine Attorney General revealed that the lengthy investigation impacted quite a large number of people, with Sax reporting over 228,000 individuals exposed.

While it is sometimes impossible to conduct an investigation within a short time, it’s difficult to imagine how impacted individuals could protect themselves without being aware that their data had been exposed.

Meanwhile, 18 months is more than enough time for attackers to exploit the stolen details for nefarious purposes. However, Sax is adamant that no customer details were exploited due to the hacker attack.

“We emphasize that we have no evidence of any actual or attempted misuse of this information,” Sax’s breach notice reads.

The company also said it will provide impacted individuals with 12 months of complimentary credit and dark web monitoring services, as well as identity restoration and credit protection services.

Based in New Jersey, US, Sax provides customers with accounting and other services, positioning itself as an advisor to businesses and high-net-worth individuals. Sax reported revenue exceeding $100 million with over 400 staff under its roof.