Mizuno USA Data Breach: Hackers Had Access for Two Months

Mizuno USA, a subsidiary of the Mizuno Corporation and one of the world’s leading sporting goods manufacturers, recently confirmed a data breach that saw unknown attackers gain unauthorized access to its network for over two months. The company revealed in data breach notification letters that sensitive files were stolen from its systems between August and October 2024.

Details of the Breach

Mizuno USA, headquartered in Peachtree Corners, Georgia, specializes in manufacturing and distributing sports equipment and apparel across North America. The company produces gear for sports including golf, baseball, volleyball, softball, swimming, and tennis.

The breach was discovered on November 6, 2024, when Mizuno detected suspicious activity within its internal network. A subsequent investigation determined that cybercriminals had accessed certain systems and exfiltrated documents containing personal data from August 21, 2024, to October 29, 2024. This unauthorized access allowed hackers to periodically copy files without detection.

Mizuno USA worked swiftly to assess the scope of the breach. By December 18, 2024, a detailed review of the stolen files was completed, and the company started notifying affected individuals shortly afterward. While Mizuno has not disclosed the total number of impacted users, it confirmed that personal information such as names, Social Security numbers, financial account details, driver’s license information, and passport numbers were among the compromised data.

Company’s Response and Recommendations

To mitigate the impact of the breach, Mizuno USA is offering a year of free credit monitoring and identity protection services to affected individuals. The company has also advised those impacted to closely monitor their financial accounts and credit reports for any suspicious activity that might indicate identity theft or fraud.

Mizuno takes the security and privacy of our customers seriously, and we regret any inconvenience this incident may have caused, the company stated in its notification letters.

Breach Linked to BianLian Ransomware Group

While Mizuno USA has not publicly disclosed details about the cybercriminals behind the breach, the notorious BianLian ransomware gang claimed responsibility for the attack in early November 2024. The group is known for targeting private corporations and critical infrastructure organizations worldwide.

BianLian has been active since June 2022 and initially launched ransomware attacks to encrypt victims’ files. However, after cybersecurity firm Avast released a free decryptor for its ransomware in January 2023, the group transitioned to extortion-only tactics, focusing on stealing data and threatening to release it if ransom demands were not met.

Previous Mizuno USA Cyberattack

This is not the first time Mizuno USA has fallen victim to cyberattacks. In February 2022, the company suffered a ransomware attack that caused widespread business disruptions, including phone system outages, order processing delays, and website accessibility issues. At the time, the nature of the attack was not disclosed, but it significantly affected the company’s operations.

Since claiming responsibility for the latest breach, the BianLian group has updated Mizuno USA’s entry on its dark web leak site, posting screenshots of allegedly stolen internal documents. These include a spreadsheet detailing the company’s expenses following the 2022 attack, as well as confidential business, finance, and HR records.

Ongoing Cybersecurity Challenges

The Mizuno USA breach highlights the ongoing cybersecurity threats facing corporations worldwide. As ransomware gangs evolve their tactics, organizations must bolster their cybersecurity defenses to prevent such incidents. Cybercriminals are increasingly relying on data theft and extortion rather than traditional ransomware encryption, making data protection and proactive monitoring essential.

Security experts recommend that companies implement advanced threat detection systems, conduct regular security audits, and educate employees on phishing attacks and other cyber risks. Stronger encryption, multi-factor authentication (MFA), and improved access controls can also help mitigate the risks associated with unauthorized network access.

What Affected Individuals Can Do

• If you were impacted by the Mizuno USA data breach, it is crucial to take immediate steps to protect yourself from potential identity theft and fraud. Consider the following actions:
• Monitor Financial Accounts: Keep a close eye on bank statements and credit card transactions for any unauthorized activity.
• Check Credit Reports: Regularly review your credit report for signs of fraudulent accounts or credit inquiries.
• Enroll in Credit Monitoring: Take advantage of the free credit monitoring services provided by Mizuno USA.
• Enable Fraud Alerts: Contact your bank and credit bureaus to set up fraud alerts, which can help prevent new accounts from being opened in your name.
• Be Wary of Phishing Attempts: Cybercriminals often use stolen data to launch targeted phishing scams. Avoid clicking on suspicious links or providing personal information online.
• Update Account Passwords: Change passwords for online accounts, especially if you use the same credentials across multiple platforms.

Conclusion

Mizuno USA’s data breach is yet another example of how cybercriminals continue to exploit security vulnerabilities for financial gain. While the company has taken steps to support affected individuals, the incident underscores the importance of robust cybersecurity measures for businesses and consumers alike.

With ransomware groups like BianLian evolving their strategies, organizations must remain vigilant and proactive in protecting sensitive data. In an era where digital threats are becoming more sophisticated, investing in strong cybersecurity infrastructure and maintaining ongoing security awareness is no longer optional — it is a necessity.