<!--intro-->Microsoft has enlisted the help of the FBI to investigate whether secret software code for its ubiquitous Windows and Office programmes has been stolen by hackers. The security breach was discovered on Wednesday by Microsoft security staff at the company's headquarters in Redmond, Washington.<!--/intro--> <center ><a HREF='http://www.newscientist.com/'><img SRC='http://www.newscientist.com/ads/people_why.gif' BORDER=0></a></center> According to a Microsoft spokesperson in the UK, the alarm was raised when it was discovered that secret computer passwords were being emailed to the outside world. "They detected that passwords were being remotely sent to an email account in St Petersburg, Russia," she said. "It's a deplorable act of industrial espionage." Computer security experts suspect a virus known as a trojan horse, which can be hidden in an email attachment, was used by the hacker to gain access to Microsoft's network. "It seems that it was a trojan horse called "QAZ" that opens your computer to the outside world, so people can come in and control your computer remotely, read your email, delete files, do anything they want," says Graham Cluley, senior technology consultant at Sophos Anti-Virus in Abingdon, Oxfordshire. Microsoft has yet to confirm whether source code - effectively software blueprints - for products like Windows and Office had been stolen.