Various download sites have been plastering ads all over their pages for years, some of which are just for other types of software and some of them are for services. However, a new trend among these ads has emerged, adding an extra download button where there should not be one. Many users have been falling for this simple trick of putting in a big and shiny download button in ads as a method of tricking people into clicking it when they try to download the file they want.
It is really easy to be distracted by a large wrong download button. Take a hard look at what you are about to click.
In general it is always best to download a program from the developer's own site.