The Industrial and Commercial Bank of China (ICBC) was hit with a ransomware attack today, preventing the US Treasury from settling trades on behalf of other market players.

The ICBC began to restore its services this afternoon, though it was not available for comment, nor was the US Securities and Financial Markets Association (SIFMA).

Attacks such as these revolve around encrypting data in an organization, leading to the threat actors asking for a ransom in order to restore the organization’s access to its information. It is unknown whether any data has been leaked or if any ransom has been demanded or paid.

“We are aware of the cybersecurity issue and are in regular contact with key financial sector participants, in addition to federal regulators. We continue to monitor the situation,” stated a Treasury spokesperson.

The Treasury first issued this statement after a Financial Times report was released with initial details of the breach.