The cyberespionage group that stole the personal records of millions of Americans from U.S. health insurer Anthem and the U.S. Office of Personnel Management (OPM) has also reportedly breached United Airlines.
The data stolen from United includes flight manifests, which contain information on passengers, their travel origins and destinations, Bloomberg reported Wednesday citing unnamed people familiar with the investigation.
The breach may have been discovered with the help of investigators in the OPM case who built a list of other potential victims after analyzing the domain names, phishing emails and attack infrastructure used by the group, the media organization reported.
United Continental Holdings, the airline's parent company, did not immediately respond to a request for comment.
The hacker group is believed to have ties to the Chinese government and also broke into the computer systems of at least ten companies and organizations, including Anthem, according to the Bloomberg report.
Security researchers from Symantec attributed the Anthem breach to a sophisticated cyberespionage group dubbed Black Vine that has been operating since 2012 and has targeted organizations from a variety of industries including aerospace, healthcare, energy, military and defense, finance, agriculture and technology.
The OPM breach, which exposed sensitive information on 21.5 million current and former U.S. government employees, including those who underwent background checks, is not mentioned in the paper, but the Anthem attack is.
The Anthem breach was announced in February and involved the theft of 78.8 million records with names, birth dates, Social Security numbers, addresses, phone numbers, email addresses and member IDs of health insurance holders.
According to Symantec, Black Vine is a well resourced group with access to exploits for previously unknown vulnerabilities -- zero-day exploits -- through an attack platform called the Elderwood framework that is shared by multiple cyberespionage groups, all based in China. The group also uses three custom malware programs known as Hurix, Sakurel and Mivast.
While United Airlines is not mentioned as a Black Vine victim in Symantec's white paper, there is circumstantial evidence that the group has an interest in airlines.
In May 2014, security researchers from Trend Micro reported in a blog post that a spear phishing campaign directed at an unnamed major global airline used Citrix products as a lure. The rogue emails contained a URL that appeared to be for the targeted airline's Citrix XenApp login page, a product that the organization actually used.
The URL, however, led to a page that distributed an executable file that was actually the Hurix backdoor, the Trend Micro researchers said at the time.
The blog post has since been removed from Trend Micro's website, but it still exists indexed in full on some other websites.
On July 8, United Airlines was forced to temporarily suspend all U.S. flights because of computer problems, following a similar incident on June 2. No connection was found between the July 8 downtime and the security breach, but a possible connection to the June 2 incident has not been ruled out, Bloomberg reported, citing two unnamed sources close to the investigation.