The virus, dubbed W64.Shruggle by Symantec, seems mainly to be an experiment to test the concept of a 64-bit infecter and is not actively spread, said Alfred Huger, senior director of security at Symantec.
"The most interesting thing about this is that virus writers are already developing for the 64-bit platform," he said.
Symantec got a copy of the virus from an antivirus newsgroup the company monitors, Huger said. The virus, even if released on the Internet, would not spread, he added, because the Windows software that the program exploits has not yet been released by Microsoft. Some developers are trying out the 64-bit extensions for Windows, but the software is still being tested. The virus will not run on 32-bit versions of Windows, such as Windows 2000 and Windows XP, owned by the vast majority of Microsoft users.
"This is for the future, when this stuff comes out of beta," Huger said.
That a virus for 64-bit Windows has been developed so early is somewhat ironic, since 64-bit processors such as AMD's Opteron have specific features to. That protection is targeted at worms and other attacks that, unlike e-mail viruses, are triggered without having to trick users.
While the digital pest is little threat, it does indicate that virus writers are thinking ahead. Such "proof of concept" programs tend to be aimed at identifying vulnerabilities, not exploiting them. Other recent viruses targeted at new platforms include two programs that aimed toused by many smart phones.
"They prove that there is a viable threat," Huger said.