Chainalysis disclosed a security incident affecting all users, revealing that customer information—including names, usernames, password hashes, and active tokens—was exposed to malicious actors. The company detected the breach on Monday and immediately removed access to its Reactor and Data Solutions platforms during the ongoing investigation. No evidence currently suggests that investigation data was accessed or attribution data manipulated. However, after detecting abnormal activity today, Chainalysis took its KYT service (both user interface and API), address screening products, and login page offline. The company directly notified customers whose KYT accounts showed signs of unauthorized access. Chainalysis plans to begin restoring access to KYT and address screening services starting tomorrow, requiring all users to reset passwords and rotate API keys. Remediation efforts continue for Reactor and Data Solutions restoration.