Web users who fail to keep their antivirus and anti-spyware software up to date may find themselves unable to recoup any losses which occur via their online banking accounts.

According to security firm Finjan, the new UK voluntary Banking Code, which has been produced by the British Bankers' Association (BBA), specifies that those who bank online must be able to prove they are not "acting without reasonable care".

"The new code, specifically sections 12.9 and 12.11, places the onus on customers to take reasonable care and make sure that their antivirus and anti-spyware software are up to date," said Yuval Ben-Itzhak, chief technology officer at Finjan.

"If not, customers might be held responsible for losses on their online banking account," he added. According to Ben-Itzhak this could potentially include banks rejecting online fraud claims upfront.