From Finextra.com: The head of the British security service has sent a confidential letter to more than 300 chief executives and security chiefs at banks, accountants and legal firms warning them of a Web-based attack from state organisations in China. In an unprecedented move, Jonathan Evans, director general of MI5 has warned business leaders and security chiefs that Chinese state organisations have been carrying out espionage against vital parts of of the UK economy, including the computer systems of financial services firms. It is thought the letter warns companies of the possible threat from an electronic hack attack by Chinese state organisations, which are designed to defeat IT security systems to gain sensitive information. The letter acknowledges the strong economic and commercial reasons to do business with China, but highlight the need to manage the risks involved. Some reports state that among the techniques used by Chinese groups are custom trojans which have been designed to hack into computer networks and steal confidential data.