Symantec has issued a warning to computer users to update their anti-virus tools. The word of caution follows the discovery of the information pilfering botnet, which has infected 1,100 NHS computers.

Symnatec revealed in a blog that it has been observing two FTP servers which have been associated with Qakbot botnet. The security giant discovered that the virus had been found to have uploaded 4GB of confidential information in just two weeks.

It has been revealed that the data comprises online banking and credit card information, social network and webmail credentials and internet search histories.

The company revealed in the blog, "One unusual aspect of Qakbot is that, even though its purpose is to steal information associated with home users, it has also been successful at compromising computers in corporate environments and government departments".

It was reported that virus has infected and compromised 100 computers on a Brazilian regional Government network. It has also infected a number of NHS computers in the UK. However, the company maintains that there is no sufficient evidence to reveal that customer or patient data has been pilfered owing to the infection.