The NASA confirmed its laptops carried aboard the International Space Stations in July were hit by the Gammima.AG computer virus.

The virus was first noticed in August 2007 when the laptops were still on Earth. The laptops were used by the astronauts to monitor their nutrition programs and send emails back to Earth. It got infected because the laptops apparently had no anti-virus software.

NASA assured SpaceRef, which broke the story, that the ISS' control system or command was not placed at risk because of the virus. NASA is investigating how the virus managed to enter the laptops because the ISS does not have direct Internet connection. All data traffic from the ground to the spacecraft are scanned before it is transmitted.

The space agency's theory is that the virus might have entered through a flash or USB drive brought by an astronaut. To prevent a repeat of the incident, NASA said it will put in place security systems.

The Gammima.AG virus steals passwords and log-in names and then sends the data back to a central server. It usually targets computer games such as Maple Story, HuangYu Online and Talesweaver.