SEOUL, Sept. 4 (UPI) -- South Korea's No. 5 credit card issuer, Lotte Card, was hacked last month, promping the country's financial regulator to carry out an on-site investigation. The Financial Supervisory Service said Thursday that the watchdog formed a team with the state-run Financial Security Institute to conduct the probe into Lotte Card, which has 9.65 million customers. "On Sept. 1, Lotte Card reported that the hacking occurred. Accordingly, an on-site inspection was immediately