Two unnamed "people familiar with the matter" told Bloomberg that the hackers appeared to be looking for research, intellectual property or other private information that they can sell on the underground market.

CNN: Doug Gross,

This is no accident: the place was built from the ground up to be the best, with no expense spared, including extensive hidden underground tunnels so you never see maids or room service staff walking around the low rise, spread out property.

FORBES: Las Ventanas al Paraiso, Los Cabos, Mexico