Unless you are defending from the NSA or something like that, I don't think anyone has the resources to do that kind of attack, even if in theory it's possible.

Unless you are defending from the NSA or something like that, I don't think anyone has the resources to do that kind of attack, even if in theory it's possible. Also, if you have that level of paranoia, you probably don't invite people to present in your office. Yes, leaving around a USB drive would be easier, would also be easier to attach something to the first network port you can find, or attack some weak target in the network (for example, ask to use the printer to print something, and install something on them, printers are super vulnerable and the firmware gets never updated, also because the company that manages the printers is usually an external company with little knowledge about informatics in general).