Original URL: http://www.theregister.co.uk/2004/05/28/itanic_virus/
First 64-bit Windows virus sighted
Rugrat poses no immediate risk
Anti-virus researchers at Symantec yesterday spotted the first virus capable of infecting 64-bit Windows systems.
Rugrat  was created to prove a point rather than to be released into the wild. The proof-of-concept virus poses no immediate risk to Itanic users, but as the population of IA64 systems grows that risk of 64-bit worms will also increase. The virus is also capable of infecting 32-bit computers running 64-bit emulation software.
Symantec explains that Rugrat uses an unusual method "Thread Local Storage" structures to execute malicious code. The virus is capable of infecting files that are in the same folder as it and in any subfolders. "W64.Rugrat.3344 is a fairly simple proof-of-concept virus. However, it is the first known virus to attack 64-bit Windows executables on IA64 systems intentionally, and it does so successfully," the company explains. It adds that Rugrat uses a small number of Win64 API's from three different libraries to avoid crashing systems during infections.
The author of Rugrat has also created a number of other proof-of-concept viruses (the Chiton  strain), according to Symantec. ®