Dutch Bitcoin broker Bitonic hacked as Bitcoin stolen from three customers

Bitcoin broker Bitonic has suffered a security incident in which hackers gained access to part of its internal systems. During the attack on Sunday evening, 25 October, small amounts of Bitcoin disappeared from the accounts of three customers. The company confirmed the incident on 26 October and said all affected customers have now been fully compensated. Personal data belonging to other customers may also have been viewed.

Hackers gain access to login credentials

According to Bitonic, unauthorised parties exploited a vulnerability to gain access to a system that processes login credentials. This allowed the attackers to modify data relating to various accounts.

Unauthorised Bitcoin withdrawals took place from three customers. Login credentials were also changed for two accounts. Bitonic did not disclose exactly how much Bitcoin disappeared. The company said only that the amounts were small.

As soon as Bitonic detected the attack, it took the affected systems and its own hot wallet offline as a precaution. A hot wallet is a crypto wallet connected to the internet, which means it can be used to carry out transactions quickly.

The vulnerability was then fixed and the systems were restored.

According to the official Bitonic website, cold wallets were not affected. These are wallets that are not directly connected to the internet and are generally used to store larger amounts of Bitcoin securely.

Personal data may also have been viewed

Although the direct financial damage remains limited, Bitonic is investigating whether the attackers gained access to personal data belonging to other customers.

The company cannot currently rule out fully that personal data was viewed. Based on its initial findings, this does not appear to have happened, but the investigation is still ongoing.

According to Bitonic, the attackers’ access was limited to the system containing login credentials. Other internal systems were not affected.

The company is meanwhile taking additional security measures and informing the relevant regulators. All three customers who lost Bitcoin will receive their funds back in full.

Bitonic advises customers to review security

After the incident, Bitonic is calling on customers to check their account security. Users who use two-factor authentication via email or SMS are advised in particular to switch to an authenticator app with TOTP.

The company also advises customers to change passwords if they are also used for other services.

Customers can temporarily block Bitcoin withdrawals through the Bitonic app. They can also set a personal anti-phishing phrase to make official messages easier to recognise.

Bitonic also warns about suspicious messages that ask for passwords, login codes or recovery phrases.

Service has now fully resumed. The company continues to investigate how the attackers gained access and what data may have been involved.