United detected a cyber attack into its computer systems in May or early June; Bloomberg reported, citing some unnamed sources familiar with the matter.
The same sources say that the hackers responsible for the data breach in United's systems are the same group of China-backed hackers that successfully carried out several other large heists, including the United States' Office of Personnel Management and the health insurer Anthem Inc.
Dangerous Intentions: United Airlines Data Breach
The stolen data includes manifests, which contain information on flights' passengers and their origins and destinations, meaning that the hackers have "data on the movements of Millions of Americans."
Since United Airlines is the world's second-largest airline and major contractor for U.S. government travel, experts say that the vast cache of information could be used to track the movements of specific government or military officials.
Bloomberg also speculated that the combination of security-clearance records from OPM, insurance records from Anthem, and now travel records from United, could be used by hackers to blackmail Americans working in defense and intelligence.
United Airlines didn't immediately respond to the comment.
Although the recent data breach in United Airlines strongly suggests the company to improve its cyber security, United already launched a bug bounty program in May in an effort to find security holes in its products.
Two weeks ago, United paid two hackers more than 1 Million frequent-flyer miles each for finding multiple security vulnerabilities in the Airline's IT system.
