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.
Computer security outfit Finjan has recently conducted a study prompted by the increased volume of attacks coming from China. Finjan's Malicious Code Research Center (MCRC) claims to have detected malicious activity by groups that distribute their content using obfuscated code and a network of Websites to bypass traditional information security technology.
The firm says it investigated a sophisticated attack that used zero-day exploits (malware for which there is no security patch) as well as other new hacking techniques that appeared to derive from Web sites belonging to a Chinese governmental office.