Guidance Software had to do a forensic investigation on its own systems after a hacker broke in and accessed records, including credit card data, of thousands of customers. The attack occurred in November, but wasn’t discovered until Dec. 7, John Colbert, chief executive officer of Guidance, said in an interview Monday. The attack exposed data on thousands of the company’s customers, including 3,800 whose names, addresses and credit card details were exposed, he said…
