It's megaup not the zip archive itself, if you load megaup without adblock or similar you will get a false file that downloads without your consent e.g you click to get Walkthrough.pdf a download of Walkthrough.pdf.exe starts, you would have to click download again to finally get your pdf. It isn't a virus just scummy behaviour and adware, the exe is an installer for stuff like opera browser etc
I just switched off my adblocker and had to click download 4 times to get the cg getting the installer the first 3
View attachment 264155
I guess the best bet would be for users to have a decent adblocker.