MADISON, Wis. — CUNA Mutual has amplified two warnings from Visa USA about hackers seeking to steal cardholder information by compromising financial institution computer systems and networks.

Generally hacker attacks aimed at stealing cardholder information have mostly targeted 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.