Cryptocurrency exchange Coinbase announced that the recent data breach exposed data belonging to 69,461 individuals.
Coinbase disclosed that a data breach impacted 69,461 individuals after overseas support staff improperly accessed customer and corporate data.
Coinbase recently revealed that rogue contractors stole data on under 1% of users and demanded $20M; the data breach was initially disclosed in an SEC filing.
On May 11, 2025, the company received a ransom demand from a threat actor claiming to have customer and internal data. The attacker claimed to have paid overseas contractors in support roles to extract this information from Coinbase’s internal systems, leveraging their legitimate access.
Coinbase revealed that it had detected unauthorized data access by support personnel in the past months, and promptly terminated those involved, boosted fraud monitoring, and alerted impacted users. After a ransom email in May 2025, the company confirmed the breach was part of a single coordinated campaign that successfully exfiltrated internal data.
“These instances of such personnel accessing data without business need were independently detected by the Company’s security monitoring in the previous months. Upon discovery, the Company had immediately terminated the personnel involved and also implemented heightened fraud-monitoring protections and warned customers whose information was potentially accessed in order to prevent misuse of any compromised information.” reads the filing with SEC. “Since receipt of the email, the Company has assessed the email to be credible, and has concluded that these prior instances of improper data access were part of a single campaign (the “Incident”) that succeeded in taking data from internal systems. The Company has not paid the threat actor’s demand and is cooperating with law enforcement in the investigation of this Incident.”
The security breach did not expose passwords, private keys, or customer funds. Exposed data included contact details, partial SSNs and bank info, ID images, account history, and limited internal documents.
Compromised data includes:
- Limited corporate data (including documents, training material, and communications available to support agents).
- Name, address, phone, and email;
- Masked Social Security (last 4 digits only);
- Masked bank-account numbers and some bank account identifiers;
- Government‑ID images (e.g., driver’s license, passport);
- Account data (balance snapshots and transaction history); and
- Limited corporate data (including documents, training material, and communications available to support agents).
In data breach notifications filed with the Office of Maine’s Attorney General, Coinbase said that 69461 individuals were impacted.
“Criminals targeted our customer support agents overseas. They used cash offers to convince a small group of insiders to copy data in our customer support tools for less than 1% of Coinbase monthly transacting users. Their aim was to gather a customer list they could contact while pretending to be Coinbase—tricking people into handing over their crypto.” reads the statement published by the company on its website. “They then tried to extort Coinbase for $20 million to cover this up. We said no.“
Coinbase will reimburse scammed retail users after verification, it is also opening a new support hub in the U.S. and adding stronger security controls and monitoring across all locations. The company boosted investment in insider-threat detection and response, is simulating threats to find weaknesses, and is keeping users informed throughout the investigation.
Coinbase estimates $180M–$400M in costs from the breach, mainly for remediation and customer reimbursements. The final impact remains under review.
Follow me on Twitter: @securityaffairs and Facebook and Mastodon
(SecurityAffairs – hacking, data breach)
