FBI investigating hack at Sony Pictures Entertainment

Some films were reportedly stolen in the attack, possibly including the Brad Pitt thriller Fury

The Federal Bureau of Investigation has confirmed it is investigating a hack into Sony Pictures Entertainment's network last week.

The hack took down the firm's email systems and paralysed its network.

A group called Guardians of Peace took credit for the attack, flashing the message "hacked by #GOP" on screens.

The FBI said that "the targeting of public and private sector computer networks remains a significant threat.''

Previously, Sony has said the firm was investigating the "IT matter".