Google Inc. and Intel Corp. were logical targets for China-based hackers, given the solid-gold intellectual property data stored in their computers. An attack by cyber spies on iBahn, a provider of Internet services to hotels, takes some explaining.

iBahn provides broadband business and entertainment access to guests of Marriott International Inc. and other hotel chains, including multinational companies that hold meetings on site. Breaking into iBahn's networks, according to a senior U.S. intelligence official familiar with the matter, may have let hackers see millions of confidential e-mails, even encrypted ones, as executives from Dubai to New York reported back on everything from new product development to merger negotiations.

More worrisome, hackers might have used iBahn's system as a launching pad into corporate networks that are connected to it, using traveling employees to create a backdoor to company secrets, said Nick Percoco, head of Trustwave Corp.'s SpiderLabs, a security firm.