Fake Internet postcards circulated through electronic mails worldwide carry links to a deadly virus known as Zeus Bot, according to a new study.
Gary Warner, computer forensics director at the University of Alabama at Birmingham (UAB), who led the study, said, Zeus Bot has been named America's most pervasive computer virus, reportedly affecting some 3.6 million computers in the US.
"These fake postcards ask users to click and download to view the contents, and as soon as they do so, the Zeus Bot infects their computers," Warner said.
Once on a computer, Zeus Bot will give cyber criminals access to passwords and account numbers of banks and other sensitive online accounts.
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 onto unaware users' computers.
Once the virus is on a computer it is able to steal website data from victims' machines. It keeps track of infected machines throughout the world and is equipped with tools that allow the criminals to prioritise the banks they want to strike, Warner said.
"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 said.
"Instead, type the address for the site that the message is coming from into your web browser and log in. If the site has an important message for you, you will be able to find it," he added.