CME Group, the parent company of the Chicago Board of Trade and other exchanges, said Friday that it was hacked in July and that some of its customers' information was compromised.

The Chicago-based company said that trading and other services were not affected by the attack. Customer information from its CME ClearPort platform was compromised. CME ClearPort is a platform where customers report over-the-counter trades in energy and commodity markets.

The incident is now a subject of a federal criminal investigation. CME Group is cooperation with law enforcement, it said.