The threat of cyberattacks against accounting professionals is growing rapidly. In 2025, ransomware and data breaches are more than just IT issues—they're critical compliance concerns. Whether you’re a bookkeeper, CPA, or accounting firm owner, the risk of client data exposure can damage your reputation and lead to major legal consequences.
In this guide, we explore major cybersecurity breaches that have affected top firms around the world and share actionable steps to protect your accounting practice, stay compliant with data protection laws, and maintain trust with your clients.
Hackers exploited reused credentials in a credential-stuffing attack, affecting nearly 200,000 accounts. This underscores the compliance risks of poor password policies in cloud-based accounting environments.
Deloitte, one of the Big Four accounting firms, suffered a significant email system breach. Hackers bypassed protections by exploiting an admin account lacking multifactor authentication. Sensitive client data stored on Microsoft Azure was exposed. This breach underlines the importance of strong authentication protocols for data compliance.
BDO uncovered a breach during routine compliance auditing. Over 100,000 client records were stolen, including Medicare numbers and claim information, resulting in $20M in damages. The case highlights the need for regular audits and secure data storage policies.
A delayed discovery of a security flaw exposed the data of 1.5 million clients. EY’s case is a reminder for accounting firms to ensure continuous security monitoring and staff training to remain compliant with UK’s data protection laws.
KPMG’s breach lasted over three weeks before discovery, resulting in leaked personal and financial client data. Accountants must prioritize secure access controls and breach detection protocols to align with Canadian compliance standards.
Whether you're a solo bookkeeper or managing a mid-size firm, here are the top ways to strengthen your cybersecurity posture and maintain compliance with privacy regulations.
Require MFA for every login. This one step dramatically reduces unauthorized access risk and ensures compliance with most data protection frameworks.
Speed matters. In a crisis, the faster you can restore your client’s data, the more trust you retain. Read more on recovery time expectations here: https://wowzerbackupandrestore.com/2023/01/03/why-just-having-a-backup-of-your-cloud-accounting-data-is-not-enough/
Back up your accounting software, cloud files, and emails daily. Audit your backup process monthly and ensure retention policies are documented and compliant.
Prepare a written DRP detailing how your firm will respond to a breach. Include:
Your employees are your first line of defense. Regular training prevents phishing, improves compliance awareness, and reduces breach risk.
Cybersecurity is now an accounting compliance issue. Clients expect you to protect their data—and so do the regulators. Take proactive steps:
Whether you're a CPA, bookkeeper, or small firm, being secure and compliant will define your resilience and reputation in 2025.