MADISON, Wis. — CUNA Mutual Group has issued a security alert which builds on similar alerts from Visa USA that warn of hacker attacks on the card security systems of U.S. financial institutions.

Generally hacker attacks aimed at stealing card holder information have aimed mostly at retailers, but the alert indicates that this may be changing. The insurer specifically recommended credit unions have a system in place to detect network intrusions, have a host-based intrusion detection system and to guard against having "poorly configured" firewall procedures.

Visa also recommended financial institutions contract with independent third parties to conduct security assessments and to pay close attention to security procedures at key suppliers, particularly those charged with handling cardholder information.