The FBI has reportedly issued a confidential report to US retailers warning that more cyber attacks like the ones recently suffered by Target and Neiman Marcus will occur. The FBI has discovered in the past year there have been at least 20 attacks using the same type of malware used against Target. On the other side, Neiman Marcus, US said about 1.1 million customer payment cards may have been exposed during a data breach at the privately owned luxury department store chain from July 16 to Oct. 30 last year.