Robert Arshagouni, an accounting and bookkeeping practice based in Chatsworth, California, has notified clients that an unauthorized party accessed certain internal systems earlier this year. The notice explains that sensitive personal information, including Social Security numbers, may have been exposed as a result.
Businesses that maintain financial and identity records for their clients, including accounting firms, are expected to take reasonable steps to secure that information from unauthorized access.
Robert Arshagouni’s Data Breach Investigation
According to a notice filed with the California Attorney General and dated August 5, 2026, Robert Arshagouni was alerted to a potential cybersecurity event and immediately began an investigation. That investigation determined that between January and February 2026, an unauthorized person gained intermittent access to certain systems and the information stored on them. The firm reviewed the potentially affected data to determine whether it contained sensitive information and whose information it involved.
A related notice was also filed with the Massachusetts Attorney General, dated June 29, 2026, reporting that the affected system contained names, Social Security numbers, and financial account information. That filing reported one Massachusetts resident as affected, while the California notice does not specify a total number of individuals notified. Multi-state breach notices filed on different dates and reporting different per-state figures are a normal part of the regulatory process for companies with clients across several states, not evidence of inconsistent recordkeeping.
Robert Arshagouni has not publicly disclosed the specific cause of the unauthorized access, such as whether it stemmed from a phishing attack, a compromised credential, or a vulnerability in a third-party system. The firm has stated that it notified law enforcement and relevant regulatory authorities, and that it is reviewing and enhancing its existing data security policies and procedures.
Accounting and bookkeeping firms are frequent targets for cybercriminals precisely because they concentrate exactly the kind of information identity thieves want in one place: Social Security numbers, financial account details, and tax records tied to real names and addresses. A breach at a firm like this can be especially consequential for affected clients, since the exposed data often goes well beyond what a typical retail or subscription-service breach would include.
When Social Security numbers and financial account information are both involved in the same incident, affected individuals face a materially higher and longer-lasting risk of identity theft, tax fraud, and unauthorized account activity than breaches involving only contact information. Security researchers have consistently found that stolen SSNs paired with financial details are especially valuable on illicit marketplaces because they enable a wider range of fraud, from opening new lines of credit to filing fraudulent tax returns in a victim’s name.
The gap between when unauthorized access reportedly began (January-February 2026) and when notice letters went out (as late as August 2026 for California residents) is not unusual for breaches involving a forensic investigation, but it does mean affected individuals should assume their information could have been exposed for several months before they were formally notified, and should act accordingly.
When Did This Breach Occur?
Robert Arshagouni’s California notice states that an unauthorized person had intermittent access to certain systems during January and February 2026. The firm’s investigation into the scope of the incident concluded before notices were mailed, with the California notice dated August 5, 2026, and a related Massachusetts notice dated June 29, 2026.
What Information Was Breached?
The California notice confirms that the exposed information included names and Social Security numbers. A related filing with the Massachusetts Attorney General additionally lists financial account information as part of the data affected by this incident. Robert Arshagouni has not indicated whether every notified individual had the same categories of information exposed, so affected individuals should review their own letter for details specific to them.
What You Can Do
Individuals who received a notice from Robert Arshagouni should take the following steps:
- Enroll in the complimentary credit monitoring offered in the notice before the enrollment deadline (November 5, 2026, for California recipients).
- Place a fraud alert or credit freeze with Equifax, Experian, and TransUnion.
- Request free copies of your credit reports at annualcreditreport.com and review them for unfamiliar accounts or inquiries.
- Monitor bank and credit card statements closely for unauthorized activity over the next 12 to 24 months.
- Report any suspicious activity immediately to your financial institution and consider filing a report with local law enforcement or the FTC.
File a Data Breach Lawsuit Against Robert Arshagouni
If you received a data breach notice from Robert Arshagouni, or believe your personal information was exposed in this incident, you may have legal options. Companies that handle sensitive financial and identity information have a responsibility to protect it, and affected individuals may be entitled to compensation for the risks and burdens created by a breach like this one.
Contact us at Class Action U, where we’ll connect you with a lawyer skilled in class action lawsuits. If you’ve been contacted about this breach, received notice, or discovered you were impacted, fill out our quick, easy, and secure form to sign up. There is no cost to reach out to our legal partner and no obligation after speaking with someone from our team.
