Cyber shoplifting is set to cause a major headache for retailers over Christmas, according to a report from security consultancy NTA Monitor.

The consultancy reported that by manipulating payment details on the back-end payment gateway, cyber shoplifters can change the amount they have paid for items, meaning the retailer is out of pocket and is forced to make up the difference.

According to NTA’s figures, 85 per cent of retailers online have experienced fraud in the year to April 2008, and 64 per cent said internet fraud had increased.

Roy Hills, technical director at NTA Monitor, said: “As a PCI DSS Council Approved Scanning vendor, we know only too well the serious situations that a company with significant security vulnerabilities can find itself in. Internet fraud is on the increase and ‘cyber shrinkage’ looks set to get worse in the lead up to Christmas unless retailers get their shop in order.”

NTA Monitor has released three main tips for online retails over Christmas: check items against the amount paid and the currency before they are dispatched; use character whitelists to validate all client input; and carry out high-level testing of online applications to identify weaknesses within the system.