I have been reading about the Stuxnet virus for sometime now. It seems to be a very dangerous virus, with many of the first of it's kind features. This virus attacks SCADA systems. It installs code into the PLC and has the capability of hiding itself from detection. It then can cause the control systems to operate erratically and cause subtle but substantial damage.
Jeffrey Carr in his blog here, claims that INSAT-4B was probably brought down by Stuxnet. ISRO has claimed that Stuxnet could not have "killed" the satellite as it is not built around the PLC which the virus is programmed to attack and that it has it's own custom code to program Siemen's devices.
Obviously, the most talked about attack is the target of the nuclear reactors in Iran, the extent of the damage is yet to be fully known. It is rumored that this virus is so sophisticated that it is not possible to have been created without "state-support".
Maybe we are headed towards the first "cyber-warefare" of our times.
More information about the virus:
Symantec
Wikipedia
