The attacks, which go well beyond typical cybercriminal operations, have claimed thousands of victims dating back to 2009 and continue to do so, Kaspersky Lab, the world's largest private security firm, shows in a report published on Monday.
Executives from the auto, outsourced manufacturing, cosmetic and chemical industries have been hit, the security firm said. Others targeted include military services and contractors.
In 2012, the FBI issued a general warning to U.S. government officials, businessmen and academics, advising them to use caution when updating computer software via hotel Internet connections when travelling abroad.
Kaspersky's report goes further in detailing the scale, methods and precise targeting of these attacks on top business travellers.
The movements of executives appear to be tracked as they travel, allowing attackers to pounce once a victim logs on to a hotel Wi-Fi network. Hackers cover their tracks by deleting these tools off hotel networks afterwards.
"These attackers are going after a very specific set of individuals who should be very aware of the value of their information and be taking strong measures to protect it," said Kurt Baumgartner, principal security researcher for Kaspersky, the world's largest privately held cyber-security firm.
Unsuspecting executives who submit their room number and surname while logging on to their hotel room's wireless network are tricked into downloading an update to legitimate software such as Adobe Flash, Google Toolbar or Microsoft Messenger, Kaspersky said. Because attacks happen at sign-on, encrypted communications set up later offer no defence against attack.
The same elite spying crew has used advanced keystroke-logging software and encryption-breaking at multiple hotel chains across Asia, it said.
Kaspersky declined to name the executives involved or the luxury destinations targeted but said it had informed the hotels as well as law enforcement officials in affected locations.
Ninety percent of the victims came from five countries Japan, Taiwan, China, Russia and South Korea. Business travellers to Asia from Germany, Hong Kong, Ireland and the United States have also been duped, Baumgartner said.
The Kaspersky report said a key mystery remains how attackers appear to know the precise travel itinerary of each victim, which points to a larger compromise of hotel business networks that researchers say they are continuing to probe.
© Thomson Reuters 2014