New variant of the worm

According to Kaspersky Lab's security analyst Eddy Willems said that a new strain of the worm was complicating matters.

"There was a new variant released less than two weeks ago and that's the one causing most of the problems," said Mr Willems

"The replication methods are quite good. It's using multiple mechanisms, including USB sticks, so if someone got an infection from one company and then takes his USB stick to another firm, it could infect that network too. It also downloads lots of content and creating new variants though this mechanism.

"Of course, the real problem is that people haven't patched their software," he added.