The Royal Bank of Scotland's (RBS) banking platform was hacked on Friday, creating issues for customers trying to access their online accounts. The lender said a rise in internet traffic directed at its NatWest website at about 11:30 GMT was a deliberate attempt to disrupt its service.The method is known as a distributed denial of service (DDoS) attack and caused problems for some customers for about an hour today.While it is a regular occurrence at banks, they do not usually comment on such events. However RBS released a statement to customers leading on from a more serious IT crash on Monday, which left more the one million customers unable to withdraw or pay for goods."Due to a surge in internet traffic directed at the NatWest website, customers experienced difficulties accessing some of our sites today [...] at no time was there any risk to customers," RBS said.Shares rose 1.42% to 335.60p at 16:11 on Friday.RD