Chainalysis Begins Restoring Screening Tools After Security Incident

Chainalysis began a phased restoration of its Know Your Transaction (KYT) and Address Screening services Friday, Nov. 6, after taking screening tools offline in response to a security incident that exposed user information.

The blockchain analytics company said at 3:30 a.m. ET (08:30 UTC) that service restoration had started. Customers must submit trusted IP addresses for an allowlist, and users must reset passwords and rotate API keys, where applicable, before registering transactions.

Chainalysis took KYT’s interface and API, other address-screening products and its login page offline on Nov. 4 after detecting abnormal activity. The shutdown meant users could not use the login page to reset passwords at that time.

The company also disclosed that data associated with all Chainalysis users had been exposed, including names, usernames, password hashes and live tokens. Chainalysis said an “on-path attack” exposed a subset of customer passwords and that it locked affected accounts. It reported no evidence that investigation data had been accessed or attribution data manipulated.

KYT monitors cryptocurrency transactions for suspicious activity, making the service part of customers’ compliance operations.