Virus can take over power stations

IT HAS BEEN a staple of computer related spy fiction that a computer virus can take over a power station and hold a region to ransom.

Now it seems that hackers have actually written a computer virus that attacks Siemens AG's widely used industrial control systems.

And the malware, a Trojan dubbed Stuxnet, is evolving according to Sophos with a new version the insecurity company is imaginatively calling Stuxnet-B. Both versions use infected USB thumb drives to get about.

They exploit a yet-to-be-patched vulnerability in Windows that Sophos calls UPLINK. Once loaded it snuffles about looking for Siemen's Supervisory Control and Data Acquisition, or SCADA, systems.

Siemens spokesman Alexander Machowetz told Industry Week that Siemens recommends avoiding the use of a USB stick in buildings where its SCADA system is used.

Once the worm infects a Siemens SCADA system, it tries to set up communications with a remote server computer. This might then steal proprietary corporate data or potentially could take control of the SCADA system.

We are not sure how the Trojan can connect to a command and control server as SCADA systems are typically not connected to the Internet. The reason the malware is loaded onto a USB drive is that some such systems do have USB ports, however.

Infection is rare. Siemens said it has so far only identified one customer in Germany whose SCADA systems were infected by the virus. µ