BIRMINGHAM, UK: The computer forensics director at the University of Alabama at Birmingham (UAB) has said that fake Internet postcards circulating through e-mail inboxes worldwide are carrying links to Zeus Bot - reportedly America's most pervasive computer Botnet virus, which has infected 3.6 million US computers.

The director, Gary Warner, said, “Cyber criminals who are employing the Russian-language Zeus Bot software are using the fake Internet postcards as the latest mechanism to download the virus software on to unwitting users' computers. Once on a user's computer, Zeus Bot will give cyber criminals access to passwords and account numbers for bank, e-mail and other sensitive online accounts.”

The malware uses a graphical user interface to keep track of infected machines throughout the world and allows the criminals to prioritize the banks and related stolen accounts they want to strike.

A Botnet is a collection of compromised or infected computers that runs specific software that usually has been installed on computers without the user's knowledge. Botnets are also said to have self-destruction capacity.

It is reported that in early April this year, a botnet consisting of an estimated 100,000 PCs apparently destroyed itself – as its control server sent out a command that made Windows inoperable.

After siphoning off the confidential information of a user, this destruction capacity of a Botnet helps cyberpunks cut the users off the Internet to prevent them from monitoring the subsequent transactions on their accounts.

These fake postcards ask users to click and download to view the contents, and as soon as that click is made the Zeus Bot malware infects their computers. "These messages are standard in their design and carry a subject line that indicates they come from the Web site 1001 Postcards," Warner said.

"In this case and when it comes to messages that are supposedly from your bank, eBay or any other site, don't click on the links in an e-mail," Warner warned.