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.