LONDON: British retailer Marks & Spencer (M&S) said on Wednesday (May 21) a "highly sophisticated cyber" attack would cost it about £300 million (US$403 million) in operating profit, with disruption set to run into July. The attack on one of the biggest names in Britain, with 64,000 staff and 565 stores, sent shockwaves through the retail sector. It forced its online clothing operation offline, left some food shelves bare, and wiped over a billion pounds from the company's stock market value. M&