Attackers this week locked up the business of London-based ION Cleared Derivatives, a software firm that supports derivatives trading, forcing major European banks to process trades manually and prompting a major futures exchange to delay the settlement of trades for two hours.

ION Cleared Derivatives, part of ION Group which offers software designed to automate the complete trade lifecycle and the derivatives clearing process, said in a statement on its website late Tuesday that a “cybersecurity event” affected some of its services and that “the incident is contained to a specific environment, all the affected servers are disconnected, and remediation of services is ongoing.”