Chainalysis confirmed that attackers who broke into its systems in October accessed usernames, password hashes, live tokens and user-profile data such as full names, email addresses and organizational role labels. The breach also triggered "abnormal activity" on its Reactor blockchain investigation platform, Data Solutions threat intelligence platform and KYT anti-money-laundering interface, prompting the company to take those services offline while it completes critical work. Chainalysis said it has no evidence that investigation data or attribution data were accessed or altered. The firm plans to reinstate KYT and the Address Screening tool after customers supply trusted IP addresses for an allowlist, and it will require every user to reset passwords and rotate API keys. The intrusion was described as an "on-path attack" or attacker-in-the-middle, and the company hinted the actors used an AI agent, though no perpetrator has been identified. 1