Oracle’s global network of 330,000 point-of-sale (POS) payment systems has been hacked by a Russian organised cybercrime group. The breach occurred on the network run by Micros Systems, which Oracle bought in 2014. The incident was first picked up by computer security expert Brian Krebs, who contacted Oracle for comment. The firm acknowledged it has “detected and addressed malicious code in certain legacy Micros systems”. It is also asking all Micros customers to reset their passwords for the Micros online support portal.