In the video file itself none, but before being able to click to download whatever (either torrent download or streaming), there's lot of misdirection. From a certain tablet for example, I wasn't able to start a video playback _at all_ from a certain website, because ads kept popping up. In some cases, it's not obvious where to click even for experienced users.
Fake buttons definitely can initiate the download of an executable file pretending it's a movie; there's nothing unusual (tech-wise) with it. Once in while, I do experience them.
There are countermeasures in place by some browsers/versions (that is, blocking of downloads with executable extensions), but non-savvy users can be tricked - the concept of file extension/type is not so clear to them, and it also assumes that the user is giving the right attention.
