WASHINGTON - A customer in Shenzhen, China, took a new laptop out of its box and booted it up for the first time.
But as the screen lit up, the computer began taking on a life of its own. The machine, triggered by a virus hidden in its hard drive, began searching across the Internet for another computer.
The laptop, supposedly in pristine, super-fast, direct-from-the-factory condition, had instantly become part of an illegal, global network capable of attacking websites, looting bank accounts and stealing personal data.
For years, online investigators have warned consumers about the dangers of opening or downloading emailed files from unknown or suspicious sources. Now, they say malicious software and computer code could be lurking on computers before the bubble wrap even comes off.
The shopper in this case was part of a team of Microsoft researchers in China investigating the sale of counterfeit software.
They received a sudden introduction to malware called Nitol.
The incident was revealed in court documents unsealed Thursday in a federal court in Virginia. The records describe a new front in a legal campaign against cybercrime being waged by the maker of the Windows operating system, which is the biggest target for viruses.
The documents are part of a computer fraud lawsuit filed by Microsoft against a web domain registered to a Chinese businessman named Peng Yong.
The company says the domain is a major hub for illicit Internet activity, home base for Nitol and more than 500 other types of malware, which makes it the largest single repository of infected software that Microsoft officials have encountered.