A hacker doesn't have to break into a bank's computer to steal account numbers and access codes. It may be enough to set up a "spoof" Web site that closely mimics a real bank's, according to a warning issued last week by the Office of the Comptroller of the Currency. Some customers have provided financial information to sites that they thought were legitimate Web sites, according to OCC spokesperson Dean DeBuck. The fake sites weren't exact copies of the real bank sites, DeBuck says,