An infection of a worm that spreads through low security networks, memory sticks, and PCs without the latest security updates is "skyrocketing".

The malicious program, known as Conficker, Downadup, or Kido was first discovered in October 2008.
Anti-virus firm F-Secure estimates there are now 8.9m machines infected.

Experts warn this figure could be far higher and say users should have up-to-date anti-virus software and install Microsoft's MS08-067 patch.

Sophos, an Anti-Virus firm, have stated the outbreak was of a scale they have not seen for a long period of time.

"What's more, if your users are using weak passwords - 12345, QWERTY, etc - then the virus can crack them in short order," he added.

The worm searches for a common process called "services.exe" and then becomes part of that code. The worm then integrates itself into the Windows system folder as a .dll file and gives itself a 4-8 character name.

Once the worm is up and running, it creates an HTTP server, resets a machine's System Restore point (making it far harder to recover the infected system) and then downloads files from the hacker's web site.

Microsoft says that the malware has infected computers in many different parts of the world, with machines in China, Brazil, Russia, and India having the highest number of victims.

The most vulnerable machines are those typically on a company’s computer network. This is due to the worm spreading very successfully of Ethernet and USB devices.

Via BBC