Chek Tan and Company, LLP listed on Radar ransomware leak site
The threat actor group known as Radar has made a data leak claim against Chek Tan and Company, LLP.
- Published
- 2 min read
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- Ransomware group: Radar
- Country: United States
- Sector: Financial Services
- Announcement date: October 8, 2025
Radar claims data breach against Chek Tan and Company, LLP
The threat actor group known as Radar has made a data leak claim against Chek Tan and Company, LLP. This announcement was made on the group's leak site, marking a potential cybersecurity incident for the firm.
Details of the claim
On October 8, 2025, the Radar group listed Chek Tan and Company, LLP on their leak site. The threat actor claims to have obtained access to the organization's data. Information about this group is limited in the public domain, making it difficult to ascertain their specific tactics, techniques, or procedures through public records alone.
Ransomware groups often utilize leak sites as a method of double extortion. In such scenarios, attackers not only encrypt an organization's internal systems to disrupt operations but also threaten to publish sensitive data on a public platform if a ransom is not met. This pressure tactic aims to exploit the reputational and regulatory risks associated with data exposure.
Data involved in the incident
The listing names no specific data types or files. No screenshots or detailed information regarding the nature of the leaked data have been provided by the threat actor.
About Chek Tan and Company, LLP
Chek Tan and Company, LLP is a firm providing accounting, auditing, management consulting, tax management, and IRS representation services. It is based in San Francisco, California.
Potential impact and sector risks
Given that the organization operates in the financial services sector, this leak claim may pose a risk of exposing sensitive financial information belonging to clients. If the alleged data breach is verified, the organization may face legal obligations under state-level data protection laws and relevant regulations in the US. The potential exposure of such data could trigger secondary risks for clients, such as identity theft and targeted phishing attacks. Furthermore, the organization may experience reputational damage and disruptions to its operational processes.
Organizations operating within the financial services sector are frequent targets for cybercriminals due to the high value of the data they manage. When a breach is claimed, the impact often extends beyond the immediate technical disruption. The loss of client trust can be significant, and the administrative burden of investigating the breach and complying with regulatory reporting requirements can be substantial.
To defend against such threats, organizations typically implement a multi-layered security approach. This includes maintaining robust backup solutions that are isolated from the primary network, implementing strict access controls to limit data exposure, and conducting regular security awareness training for employees to prevent initial access via phishing. Furthermore, continuous monitoring of network traffic and proactive threat hunting can help identify unauthorized access before data can be exfiltrated.