Cyber-security experts say Booking.com itself has not been hacked, but criminals have devised ways to get into the administration portals of individual hotels which use the service. Hackers are increasing their attacks on Booking.com customers by posting adverts on dark web forums asking for help finding victims. Cyber-criminals are offering up to $2,000 (£1,600) for login details of hotels as they continue to target the people who are staying with them. Criminals send a Google Drive link to the staff saying that it contains an image of the passport. Instead the link downloads malware on to staff computers and automatically searches the hotel computers for Booking.com access. Why do dark webs exist ?