Trend Micro: Windows zero-day exploit for sale

An online criminal has offered to sell software that exploits an unpatched bug in Microsoft Corp.'s Windows Vista operating system, according to security vendor Trend Micro Inc.

The code was offered for sale in an underground hacker discussion forum last month, said Raimund Genes, Trend Micro's chief technology officer. The asking price? US$50,000.

Genes didn't know if the code actually worked as advertised, or whether it was even purchased, but he said that it would have been difficult for the seller to have been involved with this particular forum without providing at least one reliable sample. "I think that definitely he had something," Genes said. "The question is whether somebody paid for this."

If the offer is legitimate it would be the first serious bug reported in Vista since it was released to business customers at the end of November. The consumer version of Vista is set to ship next month.

Microsoft is investigating Trend's claims but has "not been contacted directly by any parties about this vulnerability report, nor are we directly involved in the forums in which vulnerabilities are reportedly traded," the company said in a statement.

If someone did pay for the code -- called a "zero-day" exploit -- it was purchased at a premium price. According to Genes, a similar exploit for Internet Explorer would command about $5,000. "This was way more," he said. "Maybe the person said, 'This is the first working exploit on Vista, so I can charge a premium.'"

Because Vista is not as widely adopted as Microsoft's XP or Windows Server 2003 operating systems, criminals would have fewer potential victims to attack with the code.

"To be honest [the price for a Vista zero day] should probably be lower," said Joe Telafici, vice president of Avert operations with McAfee Inc. "There's nobody to infect with it."

There have been far fewer vulnerability disclosures in the weeks up to Vista's commercial release than there were when XP was introduced, Telafici said. That's partially due to the expansion of the underground marketplace for software bugs, he said. While most hackers were motivated by the fame and glory just a few years ago, they growth of cybercrime has introduced a new breed of more stealthy professionals, security experts say.

Criminals who plan to use Vista vulnerabilities "are going to be holding them close to their chest until they are ready to release them," Telafici said. "I wouldn't be amazed if we saw vulnerabilities popping up over the next year that were found now."