A hacker who works for an American service intelligence hacked Booking.com's servers in 2016 and stole user data from the Middle East, according to a book published Thursday. The book also says the online travel agency chose to keep the incident a secret.
Amsterdam-based Booking.com made the decision after calling on the Dutch intelligence service, also known as the AIVD, to investigate the breach of the company's servers. Following legal advice, the company did not notify the affected customers or the Dutch Data Protection Authority. 
The reason; Booking.com was not legally required to do so because no sensitive or financial information was accessed.
But IT people working at Booking.com told a different story, according to the book De Machine: In de ban van Booking.com (English translation: The Machine: Under the Spell of Booking.com). The book's authors, three journalists from the Dutch newspaper NRC, say the internal name for the breach was "PIN leak" because the breach involved stolen PINs from reservations.
The book also states that the person behind the hack had access to thousands of hotel reservations in Middle Eastern countries, such as Saudi Arabia, Qatar and the United Arab Emirates. The leaked data concerned Booking.com customer names and their travel plans.
Two months after the breach, US private investigators helped Booking.com's security department determine that the hacker was an American working for a company that performed contracts for US intelligence services. The authors did not specify which agency was behind it invasion.
Hotel reservation data and travel plans are a highly sought after product for hackers working for a state. In 2013, an informant of hers NSA revealed the “Royal Concierge,” one program spies from the British GCHQ who watched reservations at 350 luxury hotels around the world. The intelligence services use this data to identify the target hotel so that they can place bed bugs in their rooms.
In 2014, Kaspersky Labs unveiled the Dark Hotel, a campaign that used hotel Wi-Fi networks to infect the devices of targeted guests with the goal of gaining access to sensitive information. The hackers behind Dark Hotel - probably working on behalf of some government - I was particularly interested in politicians and C-level executives.
The authors of The Machine reported that a Booking.com spokesperson confirmed that there was unusual activity in 2016, and that security personnel responded immediately to the incident. He also admitted that the company never revealed it because it had no legal obligation to do so.
