A nuclear power plant in Germany has been infected by malware designed to give hackers remote access to its systems.
The Gundremmingen power station, north-west of Munich, is run by the German utility RWE. According to media reports, two strains of viruses, W32.Ramnit and Conficker were discovered at the facility's B unit in a computer system retrofitted in 2008.
In a statement, the firm said these systems were used for "data processing and visualisation and part of the fuel assembly loading machine".
The malware was also discovered on 18 removable data drives, mainly USB sticks, and computers isolated from the plant's operating systems. It is unknown how the malware got onto the systems in the first place.
A spokesman told German newspaper Die Zeit that around 1,000 computers had been checked by IT staff at the firm and "no systems important to safety" had been infected.
RWE said it has increased cybersecurity measures in response to this. The power company has also informed Germany's Federal Office for Information Security (BSI), which is investigating the incident.
Tony Berning, senior manager at security firm OPSWAT, said that as attacks become more sophisticated, and digital control systems increase in complexity and levels of automation, it is increasingly difficult to prevent threats from impacting the operation of critical infrastructure.
"As a security measure, most critical infrastructure systems are air-gapped or isolated from external networks. Because of this, portable media is a primary vector for cyber-attack; it is often the only way to transport files to and from secure areas. As key attack vectors for malware, it is extremely important that extra attention is placed on securing the portable media devices that are brought in and out of a secure facility," he said.
Alex Cruz Farmer, VP of cloud at Nsfocus, said this is a "fantastic example of where the Internet of Things, as well as BYOD (Bring Your Own Device) adoption, without the consideration of security has created a huge risk to an organisation.
"Almost every person who walks around today has a USB stick or a device which can be turned into a removable drive - even your iPhone. With businesses now issuing laptops, rather than the traditional desktops, and also more of the worldwide workforces taking their work home with them, means we are, without knowing it, more susceptible to infection," he said.
