Once it broke through to the library’s virtual private network (VPN) – the remote connection that allows employees to access its network from any location – it could in theory start making its way through locked door after locked door of the library’s many online systems, trawling until it discovered emails and documents containing details such as employees’ passport scans and work contracts. It hoped these documents might tempt a single bidder to pay 20 bitcoins (about £600,000) for privileged access to all that personal information.

Source: The Guardian