"If you haven't done that already, this should be a good time to try an antivirus," they said.

This latest warning comes in the wake of a new breed of e-threats called Stuxnet, a malicious worm that emerged in July 2010. Stuxnet is one of the first malware Trojans that targets Siemen's widely-deployed Supervisory Control and Data Acquisition, or SCADA, systems which are used to monitor automated plants - from water treatment and distribution to power generators.

At the Govware conference in Singapore in September, the Lion City's Senior Minister of State for Law & Home Affairs, Associate Professor Ho Peng Kee, warned of the "catastrophic implications" should control of such industrial systems fell into the wrong hands through the use of Stuxnet".

In October, BitDefender released a free removal tool that allows users infected with Win32.Worm.Stuxnet.