The Department of Homeland Security's cybersecurity division, in an advisory on Thursday,  cautioned of “potential for significant impact on Internet operations” as a result of the weakness in the programme highlighted by Microsoft.
  
Microsoft urged users to install an update that should correct the problem. The company said it did not know of any computer viruses in circulation that were aimed at exploiting the flaw.

Symantec, one of America’s leading Internet security companies, explained that the new vulnerability is similar to the one attacked last month. As a result, a cyber-attack is imminent, the company said.
 
The flaw affects Windows NT version 4.0, Windows 2000, Windows XP and Windows Server 2003, Microsoft said.

Worms, as these particular types of viruses are known, invade computers using local connections and spread themselves.

Last month’s W32.Blaster.Worm carried a hidden message, taunting Microsoft founder Bill Gates.

“I just want to say LOVE YOU SAN!!” read the message. “billy gates [sic] why do you make this possible? Stop making money and fix your software!!”

A teenager from the US state of Minneapolis was apprehended by the FBI at the end of August in connection with the cyber attack, which disabled millions of computers world-wide.