A provider of secure web gateway IT solutions has discovered 1.4 gigabytes of data on a criminal server, including data from 40 'top-tier' businesses.

According to itpro.co.uk, Finjan has found data comprising of 5,388 unique log files from individuals, businesses and organisations on what it terms a 'drop-site' used by the crimeware.

It includes business-related email communications, bank customer data and captured outlook accounts containing email communication.

Chief technical officer of Finjan Yuval Ben-Itzhak said: "We were more surprised by the amount of business-related data that was being accessed. We usually find a lot of individual data breaches, so this is a very interesting development."

Finjan has already informed over 40 international financial institutions and law enforcement agencies.

This latest IT security scare follows news that UK businesses have experienced a ten-fold increase in attacks by computer hackers, with 96 per cent of larger businesses reporting security breaches.